@article{nunn_milikisiyants_torelli_monge_delord_shames_meriles_ajoy_smirnov_shenderova_2023, title={Optical and electronic spin properties of fluorescent micro- and nanodiamonds upon prolonged ultrahigh-temperature annealing}, volume={41}, ISSN={["2166-2754"]}, url={https://doi.org/10.1116/6.0002797}, DOI={10.1116/6.0002797}, abstractNote={High-temperature annealing is a promising but still mainly unexplored method for enhancing spin properties of negatively charged nitrogen-vacancy (NV) centers in diamond particles. After high-energy irradiation, the formation of NV centers in diamond particles is typically accomplished via annealing at temperatures in the range of 800–900 °C for 1–2 h to promote vacancy diffusion. Here, we investigate the effects of conventional annealing (900 °C for 2 h) against annealing at a much higher temperature of 1600 °C for the same annealing duration for particles ranging in size from 100 nm to 15 μm using electron paramagnetic resonance and optical characterization. At this high temperature, the vacancy-assisted diffusion of nitrogen can occur. Previously, the annealing of diamond particles at this temperature was performed over short time scales because of concerns of particle graphitization. Our results demonstrate that particles that survive this prolonged 1600 °C annealing show increased NV T1 and T2 electron spin relaxation times in 1 and 15 μm particles, due to the removal of fast relaxing spins. Additionally, this high-temperature annealing also boosts magnetically induced fluorescence contrast of NV centers for particle sizes ranging from 100 nm to 15 μm. At the same time, the content of NV centers is decreased fewfold and reaches a level of <0.5 ppm. The results provide guidance for future studies and the optimization of high-temperature annealing of fluorescent diamond particles for applications relying on the spin properties of NV centers in the host crystals.}, number={4}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Nunn, Nicholas and Milikisiyants, Sergey and Torelli, Marco D. and Monge, Richard and Delord, Tom and Shames, Alexander I. and Meriles, Carlos A. and Ajoy, Ashok and Smirnov, Alex I. and Shenderova, Olga A.}, year={2023}, month={Jul} }
 @article{nunn_milikisiyants_danilov_torelli_dei cas_zaitsev_shenderova_smirnov_shames_2022, title={Electron irradiation-induced paramagnetic and fluorescent defects in type Ib high pressure-high temperature microcrystalline diamonds and their evolution upon annealing}, volume={132}, ISSN={["1089-7550"]}, url={https://doi.org/10.1063/5.0103313}, DOI={10.1063/5.0103313}, abstractNote={Defects introduced to synthetic type Ib diamond micrometer-size particles by electron-beam irradiation were studied by electron paramagnetic resonance and photoluminescence (PL) spectroscopy as a function of e-beam fluence and post-irradiation thermal annealing. Increasing electron-beam fluence causes a substantial reduction of the substitutional nitrogen (P1) content, accompanied by progressively higher concentrations of paramagnetic negatively charged vacancies (V−) and triplet interstitials (R1/R2). Annealing results in a drastic decrease in the V− and R1/R2 content and an increase in the negatively charged nitrogen-vacancies (NV− or W15). Analysis of PL spectra allows for identification of color centers in the irradiated diamond samples and following their evolution after annealing. These data facilitate understanding of different factors contributing to the formation of color centers in diamond and promote efforts toward controlled engineering of optical centers in fluorescent diamond particles.}, number={7}, journal={JOURNAL OF APPLIED PHYSICS}, author={Nunn, Nicholas and Milikisiyants, Sergey and Danilov, Evgeny O. and Torelli, Marco D. and Dei Cas, Laura and Zaitsev, Alexander and Shenderova, Olga and Smirnov, Alex I. and Shames, Alexander I.}, year={2022}, month={Aug} }
 @article{mikheev_vanyukov_mogileva_mikheev_aleksandrovich_nunn_shenderova_2021, title={Femtosecond Optical Nonlinearity of Nanodiamond Suspensions}, volume={11}, ISSN={["2076-3417"]}, DOI={10.3390/app11125455}, abstractNote={High pressure-high temperature (HP-HT) nanodiamonds and detonation nanodiamonds have unique optical properties and are promising materials for various applications in photonics. In this work, for the first time, comparative studies of the nonlinear optical properties of aqueous suspensions of HP-HT and detonation nanodiamonds under femtosecond laser excitation are performed. Using the z-scan technique, it was found that for the same laser pulse parameters HP-HT nanodiamonds exhibited optical limiting due to two-photon absorption while detonation nanodiamonds exhibited saturable absorption accompanied by short-term optical bleaching, revealing the different electronic-gap structures of the two types of nanodiamonds. The saturable absorption properties of detonation nanodiamonds are characterized by determining the saturable and non-saturable absorption coefficients, the saturation intensity, and the ratio of saturable to non-saturable losses. The nonlinear absorption in HP-HT nanodiamonds is described with the nonlinear absorption coefficient that decreases with decreasing concentration of nanoparticles linearly. The results obtained show the possibility of using aqueous suspensions of nanodiamonds for saturable absorption and optical limiting applications.}, number={12}, journal={APPLIED SCIENCES-BASEL}, author={Mikheev, Gennady M. and Vanyukov, Viatcheslav V. and Mogileva, Tatyana N. and Mikheev, Konstantin G. and Aleksandrovich, Alexander N. and Nunn, Nicholas A. and Shenderova, Olga A.}, year={2021}, month={Jun} }
 @article{torelli_nunn_jones_vedelaar_padamati_schirhagl_hamers_shames_danilov_zaitsev_et al._2020, title={High Temperature Treatment of Diamond Particles Toward Enhancement of Their Quantum Properties}, volume={8}, ISSN={["2296-424X"]}, DOI={10.3389/fphy.2020.00205}, abstractNote={Fluorescence of the negatively charged nitrogen-vacancy (NV−) center of diamond is sensitive to external electromagnetic fields, lattice strain, and temperature due to the unique triplet configuration of its spin states. Their use in particulate diamond allows for the possibility of localized sensing and magnetic-contrast-based differential imaging in complex environments with high fluorescent background. However, current methods of NV− production in diamond particles are accompanied by the formation of a large number of parasitic defects and lattice distortions resulting in deterioration of the NV− performance. Therefore, there are significant efforts to improve the quantum properties of diamond particles to advance the field. Recently it was shown that rapid thermal annealing (RTA) at temperatures much exceeding the standard temperatures used for NV− production can efficiently eliminate parasitic paramagnetic impurities and, as a result, by an order of magnitude improve the degree of hyperpolarization of 13C via polarization transfer from optically polarized NV− centers in micron-sized particles. Here, we demonstrate that RTA also improves the maximum achievable magnetic modulation of NV− fluorescence in micron-sized diamond by about 4x over conventionally produced diamond particles endowed with NV−. This advancement can continue to bridge the pathway toward developing nano-sized diamond with improved qualities for quantum sensing and imaging.}, journal={FRONTIERS IN PHYSICS}, author={Torelli, Marco D. and Nunn, Nicholas A. and Jones, Zachary R. and Vedelaar, Thea and Padamati, Sandeep Kumar and Schirhagl, Romana and Hamers, Robert J. and Shames, Alexander I. and Danilov, Evgeny O. and Zaitsev, Alexander and et al.}, year={2020}, month={Jun} }
 @article{mikheev_mogileva_fateev_nunn_shenderova_mikheev_2020, title={Low-Power Laser Graphitization of High Pressure-High Temperature Nanodiamond Films}, volume={10}, ISSN={["2076-3417"]}, DOI={10.3390/app10093329}, abstractNote={Laser-induced graphitization of 100 nm monocrystals of diamond particles synthesized by high-pressure high-temperature (HP-HT) methods is not typically observed. The current study demonstrates the graphitization of 150 nm HP-HT nanodiamond particles in ca. 20-μm-thick thin films formed on a glass substrate when the intensity of a focused 633 nm He-Ne laser exceeds a threshold of ~ 33 kW/cm2. Graphitization is accompanied by green luminescence. The structure and morphology of the samples were investigated before and after laser excitation while using X-ray diffraction (XRD), Raman spectroscopy, atomic force (AFM), and scanning electron microscopy (SEM). These observations are explained by photoionization of [Ni-N]- and [N]-centers, leading to the excitation of electrons to the conduction band of the HP-HT nanodiamond films and an increase of the local temperature of the sample, causing the transformation of sp3 HP-HT nanodiamonds to sp2-carbon.}, number={9}, journal={APPLIED SCIENCES-BASEL}, author={Mikheev, Konstantin G. and Mogileva, Tatyana N. and Fateev, Arseniy E. and Nunn, Nicholas A. and Shenderova, Olga A. and Mikheev, Gennady M.}, year={2020}, month={May} }
 @article{farias_brown_hearn_nunn_shenderova_khan_2020, title={Nanodiamond-stabilized Pickering emulsions: Microstructure and rheology}, volume={580}, ISSN={["1095-7103"]}, DOI={10.1016/j.jcis.2020.07.030}, abstractNote={We envisage the use of hydroxylated detonation nanodiamonds (ND-OH), a relatively novel carbonaceous filler with high adsorption activity, small size, and large surface area to create Pickering emulsions. The emulsion behavior under shear and the extent to which the microstructure can rebuild after breakdown is dependent on its yield stress. Using a model system consisting of isopropyl palmitate and water stabilized by ND-OH particles, we investigate the stability of these emulsions, their microstructure and rheological behavior as a function of ND-OH concentration. Confocal microscopy reveals that increasing ND-OH concentration results in smaller droplet sizes in the emulsions. This behavior is consistent with our rheological results of higher elastic modulus G′ and yield stress of the emulsion with increased ND-OH, as the presence of smaller droplets facilitates the formation of a densely packed network. We find the rheological behavior of these emulsions to be a hybrid of colloidal gels and surfactant-stabilized emulsions, with interparticle interactions and droplets deformability dictating their elasticity and yield stress behavior. Structure recovery following large shear reveals the degree of microstructure recovery to depend on the applied stress, with the recovered modulus collapsing into a single master-curve when the applied stress is scaled by the yield stress.}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, author={Farias, Barbara V and Brown, Derek and Hearn, Allison and Nunn, Nicholas and Shenderova, Olga and Khan, Saad A.}, year={2020}, month={Nov}, pages={180–191} }
 @article{gibson_luo_shenderova_koscheev_brenner_2012, title={Electrostatically mediated adsorption by nanodiamond and nanocarbon particles}, volume={14}, ISSN={["1572-896X"]}, DOI={10.1007/s11051-011-0700-9}, number={3}, journal={JOURNAL OF NANOPARTICLE RESEARCH}, author={Gibson, Natalie M. and Luo, Tzy-Jiun Mark and Shenderova, Olga and Koscheev, Alexey P. and Brenner, Donald W.}, year={2012}, month={Mar} }
 @article{gibson_luo_brenner_shenderova_2011, title={Immobilization of mycotoxins on modified nanodiamond substrates}, volume={6}, ISSN={["1559-4106"]}, DOI={10.1116/1.3672489}, abstractNote={The effectiveness of modified nanodiamonds (NDs) for the adsorption of mycotoxins, aflatoxin B1 (AfB1) and ochratoxin A (OTA), are investigated in this paper. Binding and release mechanisms of the mycotoxins were addressed using an assortment of NDs modified by different surface treatments, including carboxylation, hydrogenation and hydroxylation, followed by isolating NDs of different sizes. Results indicate that AfB1 adsorption on NDs is directly related to aggregate size, whereas OTA adsorption is primarily centered upon electrostatic interactions that depend on the types of surface functional groups on the ND. Findings show that modified NDs with small aggregation sizes (~40 nm) have greater adsorption capacities for AfB1 than yeast cells walls and untreated NDs from various vendors, but comparable to activated charcoal. In OTA studies, positively charged NDs outperformed clay minerals, which are well-known and efficient sorbents for mycotoxins. Furthermore, ND adsorption capacities can be preserved in a wide range of pH.}, number={4}, journal={BIOINTERPHASES}, author={Gibson, N. M. and Luo, T. J. M. and Brenner, D. W. and Shenderova, O.}, year={2011}, month={Dec}, pages={210–217} }
 @article{gibson_shenderova_luo_moseenkov_bondar_puzyr_purtov_fitzgerald_brenner_2009, title={Colloidal stability of modified nanodiamond particles}, volume={18}, ISSN={["1879-0062"]}, DOI={10.1016/j.diamond.2008.10.049}, abstractNote={Colloidal stability is one of the critical factors for the use of nanodiamonds as potential enterosorbents. Although nanodiamonds are believed to be a promising enterosorbent, colloidal stability in hydrosols of raw polydispersed nanodiamonds produced by detonation is typically low. Surface modification and fractionation significantly improves colloidal stability of nanodiamond suspensions within the physiological pH range. The modification of nanodiamonds can be completed either by physical means, i.e., plasma treatments, or by chemical methods. In the current paper an analysis of the colloidal stability of detonation nanodiamonds hydrosols, which have undergone different surface modifications, is presented based on zeta potential measurements and titration experiments.}, number={4}, journal={DIAMOND AND RELATED MATERIALS}, author={Gibson, N. and Shenderova, O. and Luo, T. J. M. and Moseenkov, S. and Bondar, V. and Puzyr, A. and Purtov, K. and Fitzgerald, Z. and Brenner, D. W.}, year={2009}, month={Apr}, pages={620–626} }
 @misc{hu_shenderova_brenner_2007, title={Carbon nanostructures: Morphologies and properties}, volume={4}, DOI={10.1166/jctn.2007.2307}, number={2}, journal={Journal of Computational and Theoretical Nanoscience}, author={Hu, Y. H. and Shenderova, O. A. and Brenner, D. W.}, year={2007}, pages={199–221} }
 @article{shenderova_tyler_cunningham_ray_walsh_casulli_hens_mcguire_kuznetsov_lipa_2007, title={Nanodiamond and onion-like carbon polymer nanocomposites}, volume={16}, ISSN={["1879-0062"]}, DOI={10.1016/j.diamond.2006.11.086}, abstractNote={The current work demonstrates that nanodiamond (ND) of detonation origin and onion-like carbon (OLC) are valuable additives in multifunctional polymer composites, particularly for polymers used in microelectronic applications. We demonstrate that addition of ND to a polyimide matrix increases the thermal degradation temperature of the composites up to 30 °C and also improves adhesion. The addition of 2 wt.% of ND increases thermal conductivity of PDMS up to 15%. Finally, we also demonstrate that the addition of OLC to polydimethylsiloxane and polyurethane matrices increases the loss tangent of the composites.}, number={4-7}, journal={DIAMOND AND RELATED MATERIALS}, author={Shenderova, O. and Tyler, T. and Cunningham, G. and Ray, M. and Walsh, J. and Casulli, M. and Hens, S. and McGuire, G. and Kuznetsov, V. and Lipa, S.}, year={2007}, pages={1213–1217} }
 @article{puzyr_purtov_shenderova_luo_brenner_bondar_2007, title={The adsorption of aflatoxin B1 by detonation-synthesis nanodiamonds}, volume={417}, ISSN={["1607-6729"]}, DOI={10.1134/S1607672907060026}, number={1}, journal={DOKLADY BIOCHEMISTRY AND BIOPHYSICS}, author={Puzyr, A. P. and Purtov, K. V. and Shenderova, O. A. and Luo, M. and Brenner, D. W. and Bondar, V. S.}, year={2007}, month={Dec}, pages={299–301} }
 @misc{hu_shenderova_hu_padgett_brenner_2006, title={Carbon nanostructures for advanced composites}, volume={69}, ISSN={["1361-6633"]}, DOI={10.1088/0034-4885/69/6/R05}, abstractNote={Recent advances in the science and technology of composites utilizing carbon nanostructures are reviewed, including experimental results and modelling studies of composite properties and processing. Carbon nanotubes are emphasized, with other carbon nanostructures such as fullerenes, ultradispersed diamond clusters and diamond nanorods also being discussed.}, number={6}, journal={REPORTS ON PROGRESS IN PHYSICS}, author={Hu, Yanhong and Shenderova, Olga A. and Hu, Zushou and Padgett, Clifford W. and Brenner, Donald W.}, year={2006}, month={Jun}, pages={1847–1895} }
 @article{padgett_shenderova_brenner_2006, title={Thermal conductivity of diamond nanorods: Molecular simulation and scaling relations}, volume={6}, ISSN={["1530-6992"]}, DOI={10.1021/nl060588t}, abstractNote={Thermal conductivities of diamond nanorods are estimated from molecular simulations as a function of radius, length, and degree of surface functionalization. While thermal conductivity is predicted to be lower than carbon nanotubes, their thermal properties are less influenced by surface functionalization, making them prime candidates for thermal management where heat transfer is facilitated by cross-links. A scaling relation based on phonon surface scattering is developed that reproduces the simulation results and experimental measurements on silicon nanowires.}, number={8}, journal={NANO LETTERS}, author={Padgett, Clifford W. and Shenderova, Olga and Brenner, Donald W.}, year={2006}, month={Aug}, pages={1827–1831} }
 @article{shenderova_padgett_hu_brenner_2005, title={Diamond nanorods}, volume={23}, ISSN={["2166-2746"]}, DOI={10.1116/1.2122907}, abstractNote={Diamond nanorods are one-dimensional carbon nanostructures consisting of all sp3 bonded carbon atoms. They represent an alternative class of carbon structure to fullerene nanotubes for potential applications in nanocomposites for mechanical reinforcement and thermal management, as well as in microelectronics. Synthetic routes for creating diamond nanorods (and related structures) and recent predictions of their stability, mechanical, and thermal properties are summarized in the article.}, number={6}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Shenderova, OA and Padgett, CW and Hu, Z and Brenner, DW}, year={2005}, pages={2457–2464} }
 @article{areshkin_shenderova_schall_brenner_2005, title={Self-consistent tight binding model adapted for hydrocarbon systems}, volume={31}, ISSN={["1029-0435"]}, DOI={10.1080/08927020500044988}, abstractNote={A self-consistent environment-dependent tight binding method is presented that was developed to simulate eigenvalue spectra, electron densities and Coulomb potential distributions for hydrocarbon systems. The method builds on a non-self-consistent environment-dependent tight binding model for carbon [Tang et al., Phys. Rev. B 53, 979 (1996)] with parameters added to describe hydrocarbon bonds and to account for self-consistent charge transfer. A detailed description of the parameterization procedure is given. Case studies that examine electron emission-related properties of carbon nanotubes demonstrate the utility of the method. The results of these calculations indicate that field enhancement in the vicinity of a nanotube tip is higher for open-ended than for capped nanotubes. At the same time open-ended nanotubes exhibit a higher potential barrier in the tip region. This barrier deteriorates the coupling between conducting states in the nanotube and free electron states in vacuum, and may increase the field emission threshold.}, number={8}, journal={MOLECULAR SIMULATION}, author={Areshkin, DA and Shenderova, OA and Schall, JD and Brenner, DW}, year={2005}, month={Jul}, pages={585–595} }
 @article{areshkin_shenderova_schall_adiga_brenner_2004, title={A self-consistent tight binding model for hydrocarbon systems: application to quantum transport simulation}, volume={16}, ISSN={["1361-648X"]}, DOI={10.1088/0953-8984/16/39/018}, abstractNote={A self-consistent environment-dependent (SC-ED) tight binding (TB) method for hydrocarbons that was developed for quantum transport simulations is presented. The method builds on a non-self-consistent environment-dependent TB model for carbon (Tang et al 1996 Phys. Rev. B 53 979) with parameters added to describe hydrocarbon bonds and to account for self-consistent charge transfer. The SC-EDTB model assumes an orthogonal basis set. Orthogonality is a key element for adapting the SC-EDTB scheme to transport problems because it substantially increases the efficiency of the Newton–Raphson algorithm used to accelerate self-consistency convergence under non-equilibrium conditions. Compared to most existing TB schemes the SC-EDTB scheme is distinctive in two respects. First, self-consistency is added through the exact evaluation of Hartree and linear expansion of exchange integrals. All Hamiltonian elements belonging to the same atom are affected by charge transfer, not just the diagonal elements. The second distinction is the choice of SC-EDTB parameters; they were fitted to Mulliken populations and eigenvalue spectra rather than energies or elastic properties. The former are directly related to the conductivity and potential profile, which are essential for transport simulation. No two-centre repulsive term parametrization was performed. The functionality of the method is exemplified by computing I–V curves, non-equilibrium potential profiles and current density for a resonant tunnelling device.}, number={39}, journal={JOURNAL OF PHYSICS-CONDENSED MATTER}, author={Areshkin, DA and Shenderova, OA and Schall, JD and Adiga, SP and Brenner, DW}, year={2004}, month={Oct}, pages={6851–6866} }
 @article{zhirnov_shenderova_jaeger_tyler_areshkin_brenner_hren_2004, title={Electron emission properties of detonation nanodiamonds}, volume={46}, ISSN={["1063-7834"]}, DOI={10.1134/1.1711444}, number={4}, journal={PHYSICS OF THE SOLID STATE}, author={Zhirnov, VV and Shenderova, OA and Jaeger, DL and Tyler, T and Areshkin, DA and Brenner, DW and Hren, JJ}, year={2004}, pages={657–661} }
 @article{areshkin_shenderova_adiga_brenner_2004, title={Electronic properties of diamond clusters: self-consistent tight binding simulation}, volume={13}, ISSN={["1879-0062"]}, DOI={10.1016/j.diamond.2004.04.012}, abstractNote={A self-consistent environment-dependent tight binding method is used to examine electron emission-related properties of hydrogen passivated nano-diamond (ND) particles. For sizes larger than 2.5 nm particle bandgap was found to be equal to the bandgap of bulk diamond. Coulomb potential distributions and electron affinities of clusters were found to be insensitive to the particle size if it exceeds 1.0 nm. Tunneling probabilities for homogeneous and inhomogeneous emission models were estimated. The simulation results indicate that the low emission threshold for hydrogen passivated diamond nano-clusters is due to hydrogen-assisted emission from the edges of small unpassivated islands. Essentially the same mechanism is claimed to be responsible for good emission properties of hydrogen passivated diamond films by Ristein [Diam. Relat. Mater. 9, 1129 (2000)].}, number={10}, journal={DIAMOND AND RELATED MATERIALS}, author={Areshkin, DA and Shenderova, OA and Adiga, SP and Brenner, DW}, year={2004}, month={Oct}, pages={1826–1833} }
 @article{nazarov_shenderova_brenner_2004, title={The atomic computer simulation of triple junctions of special tilt boundaries in nickel}, volume={98}, number={4}, journal={Physics of Metals and Metallography}, author={Nazarov, A. A. and Shenderova, O. A. and Brenner, D. W.}, year={2004}, pages={339–343} }
 @article{shenderova_areshkin_brenner_2003, title={Bonding and stability of hybrid diamond/nanotube structures}, volume={29}, ISSN={["1029-0435"]}, DOI={10.1080/0892702021000049691}, abstractNote={Geometrical considerations combined with detailed atomic modeling are used to define general classes of diamond/carbon nanotube interface structures with low residual stresses and no unsatisfied bonding. Chemically and mechanically robust interfaces are predicted, supporting recent experimental studies in which structures of this type were proposed.}, number={4}, journal={MOLECULAR SIMULATION}, author={Shenderova, OA and Areshkin, D and Brenner, DW}, year={2003}, month={Apr}, pages={259–268} }
 @article{areshkin_shenderova_schall_brenner_2003, title={Convergence acceleration scheme for self-consistent orthogonal-basis-set electronic structure methods}, volume={29}, ISSN={["1029-0435"]}, DOI={10.1080/0892702031000092197}, abstractNote={A new self-consistent convergence acceleration scheme that is a variant of the Newton-Raphson algorithm for non-linear systems of equations is presented. With this scheme, which is designed for use with minimal orthogonal basis set electronic structure methods, the conventional Newton-Raphson scaling with respect to the number of atoms is enhanced from quartic to cubic. The scheme is demonstrated using a self-consistent environment-dependent tight binding model for hydrocarbons that allows an efficient and reasonably precise simulation of charge density distortions due to external electric fields, finite system sizes, and surface effects. In the case of a metallic system, self-consistency convergence starts at a high fictitious temperature, typically 1500 K. As the electron density approaches the self-consistent configuration the temperature is decreased. Typically, seven to nine iterations are required to achieve self-consistency in metallic systems to a final temperature of 300 K. For systems with a finite band gap the convergence may start at the target temperature so that temperature reduction is unnecessary, and typically two iterations are needed to achieve self-consistency. The convergence algorithm can handle extremely high applied fields and is very robust with respect to initial electron densities.}, number={4}, journal={MOLECULAR SIMULATION}, author={Areshkin, DA and Shenderova, OA and Schall, JD and Brenner, DW}, year={2003}, month={Apr}, pages={269–286} }
 @article{bachurin_nazarov_shenderova_brenner_2003, title={Diffusion-accomodated rigid-body translations along grain boundaries in nanostructured materials}, volume={359}, ISSN={["1873-4936"]}, DOI={10.1016/s0921-5093(03)00354-x}, abstractNote={A model for the structural relaxation of grain boundaries (GBs) in nanostructured materials (NSMs) by diffusion-accommodated rigid body translations along GBs is proposed. The model is based on the results of recent computer simulations that have demonstrated that the GBs in NSMs retain a high-energy structure with random translational states due to severe geometrical constraints applied from neighboring grains (J. Appl. Phys. 78 (1995) 847; Scripta Metall. Mater. 33 (1995) 1245). The shear stresses within a GB caused by non-optimized rigid-body translations (RBTs) can be accommodated by diffusive flow of atoms along a GB. This mechanism is particularly important for low-angle and vicinal GBs, the energy of which noticeably depends on the rigid body translations. At moderate and high temperatures the model yields relaxation times that are very short and therefore GBs in NSMs can attain an equilibrium structure with optimized rigid body translations. In contrast, at room temperature the model predicts that in some metals non-equilibrium structures can be preserved for a long time, which may result in the observation of grain boundary structures different from those in coarse grained polycrystals.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Bachurin, DV and Nazarov, AA and Shenderova, OA and Brenner, DW}, year={2003}, month={Oct}, pages={247–252} }
 @article{shenderova_brenner_ruoff_2003, title={Would diamond nanorods be stronger than fullerene nanotubes?}, volume={3}, ISSN={["1530-6992"]}, DOI={10.1021/nl025949t}, abstractNote={On the basis of literature ab initio data, we show that diamond nanorods would have a brittle fracture force and a zero strain stiffness that exceeds carbon nanotubes for radii greater than about 1-3 nm, depending on the orientation of the diamond nanorod. The energetic stability of diamond nanorods is predicted by molecular modeling to be comparable to single-walled carbon nanotubes. It is concluded that diamond nanorods represent an important and viable target structure for synthesis. With its exceedingly high bulk modulus and hardness, diamond has historically been considered the strongest material. Recently, however, it has been claimed based on both theory and experiment that carbon nanotubes are both stiffer and stronger along their axis than diamond. A problem with this claim is that it is difficult to make a fair comparison between these two representatives from the macro- and nanoscales unless some additional assumptions about their structure are made, for example an effective “thickness” of a sheet of carbon atoms comprising a nanotube. In this paper the mechanical properties of single-walled nanotubes (SWNTs) and multiwalled nanotubes (MWNTs) are compared to the predicted properties of an equivalent nanoscopic-scale diamond structure, namely a diamond nanorod (DNR). Our general analysis suggests that while a SWNT will have a higher strength-to-weight ratio, above a critical radius between about 1 and 3 nm (depending on the DNR structure) the force needed for brittle fracture of a DNR exceeds that of a SWNT. This higher fracture force, which at the nanoscopic scale is a less ambiguous property than fracture stress, results from the larger load-bearing crosssectional area of DNRs compared to SWNTs at the same diameter. Similarly, the calculations show that the zero strain stiffness of DNRs will exceed that of SWNTs for radii greater than about 1 nm. Experimental loading of SWNTs in ropes has yielded estimates for the tensile Young’s modulus that range from 320 GPa to 1.47 TPa, 1 and breaking strengths that range from 13 to 52 GPa (a strain of up to almost 6%), 1 values that}, number={6}, journal={NANO LETTERS}, author={Shenderova, O and Brenner, D and Ruoff, RS}, year={2003}, month={Jun}, pages={805–809} }
 @article{brenner_shenderova_harrison_stuart_ni_sinnott_2002, title={A second-generation reactive empirical bond order (REBO) potential energy expression for hydrocarbons}, volume={14}, ISSN={["0953-8984"]}, DOI={10.1088/0953-8984/14/4/312}, abstractNote={A second-generation potential energy function for solid carbon and hydrocarbon molecules that is based on an empirical bond order formalism is presented. This potential allows for covalent bond breaking and forming with associated changes in atomic hybridization within a classical potential, producing a powerful method for modelling complex chemistry in large many-atom systems. This revised potential contains improved analytic functions and an extended database relative to an earlier version (Brenner D W 1990 Phys. Rev. B 42 9458). These lead to a significantly better description of bond energies, lengths, and force constants for hydrocarbon molecules, as well as elastic properties, interstitial defect energies, and surface energies for diamond.}, number={4}, journal={JOURNAL OF PHYSICS-CONDENSED MATTER}, author={Brenner, DW and Shenderova, OA and Harrison, JA and Stuart, SJ and Ni, B and Sinnott, SB}, year={2002}, month={Feb}, pages={783–802} }
 @article{brenner_shenderova_areshkin_schall_frankland_2002, title={Atomic modeling of carbon-based nanostructures as a tool for developing new materials and technologies}, volume={3}, number={5}, journal={Computer Modeling in Engineering & Sciences : CMES}, author={Brenner, D. W. and Shenderova, O. A. and Areshkin, D. A. and Schall, J. D. and Frankland, S. J. V.}, year={2002}, pages={643–673} }
 @inbook{shenderova_brenner_2002, title={Atomistic simulation of grain boundaries, triple junctions and related disclinations}, volume={87}, ISBN={3908450683}, booktitle={Local lattice rotations and disclinations in microstructures of distorted crystalline materials: Proceedings of the International Workshop on local lattice rotations and disclinations in microstructures of distorted crystalline materials, held at Rauschenbach/Erzgebirge, April 10-14, 2000 (Solid state phenomena ; v. 87)}, publisher={Switzerland: Scitech; Enfield, N.H.: Distributed in the Americas by Trans Tech}, author={Shenderova, O. A. and Brenner, D. W.}, year={2002}, pages={205–213} }
 @misc{shenderova_zhirnov_brenner_2002, title={Carbon nanostructures}, volume={27}, ISSN={["1547-6561"]}, DOI={10.1080/10408430208500497}, abstractNote={ABSTRACT An overview of the various carbon structures with characteristic sizes in the nanoscale region is presented, with special attention devoted to the structures and properties of ‘nanodiamond’ and carbon nanotubes. The term ‘nanodiamond’ is used broadly for a variety of diamond-based materials at the nanoscale ranging from single diamond clusters to bulk nanocrystalline films. Only selected properties of carbon nanotubes are discussed, with an aim to summarize the most recent discoveries. Current and potential applications of carbon nanostructures are critically analyzed.}, number={3-4}, journal={CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES}, author={Shenderova, OA and Zhirnov, VV and Brenner, DW}, year={2002}, pages={227–356} }
 @article{shenderova_lawson_areshkin_brenner_2001, title={Predicted structure and electronic properties of individual carbon nanocones and nanostructures assembled from nanocones}, volume={12}, ISSN={["1361-6528"]}, DOI={10.1088/0957-4484/12/3/302}, abstractNote={Calculations using an analytic potential show that carbon nanocones can exhibit conventional cone shapes or can form concentric wave-like metastable structures, depending on the nanocone radius. Single nanocones can be assembled into extended two-dimensional structures arranged in a self-similar fashion with fivefold symmetry as system size is increased. Calculations of the electronic properties of nanocones indicate that a pentagon in the centre of a cone is the most probable spot for emitting tunnelling electrons in the presence of an external field. This implies that nanocone assemblies, if practically accessible, could be used as highly localized electron sources for templating at scales below more traditional lithographies.}, number={3}, journal={NANOTECHNOLOGY}, author={Shenderova, OA and Lawson, BL and Areshkin, D and Brenner, DW}, year={2001}, month={Sep}, pages={191–197} }
 @article{shenderova_brenner_omeltchenko_su_yang_2000, title={Atomistic modeling of the fracture of polycrystalline diamond}, volume={61}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.61.3877}, abstractNote={A series of molecular-dynamics simulations using a many-body interatomic potential has been performed to investigate the behavior under load of several ^001& and ^011& symmetrical tilt grain boundaries ~GB’s! in diamond. Cohesive energies, the work for fracture, maximum stresses and strains, and toughness as a function of GB type are evaluated. Results indicate that special short-period GB’s possess higher strengths and greater resistance to crack propagation than GB’s in nearby misorientation angles. Based on dynamic simulations, it was found that the mechanism of interface failure for GB’s without preexisting flaws is not that implied by Orovan’s criterion, but rather GB strength is defined by GB type instead of cleavage energy. In simulations of crack propagation within GB’s on the other hand, it was found that critical stresses for crack propagation from atomistic simulation and from the Griffith criterion are consistent, indicating that GB cleavage energy is an important characteristic of GB toughness. Crack propagation in polycrystalline diamond samples under an applied load was also simulated and found to be predominantly transgranular rather than intergranular.}, number={6}, journal={PHYSICAL REVIEW B}, author={Shenderova, OA and Brenner, DW and Omeltchenko, A and Su, X and Yang, LH}, year={2000}, month={Feb}, pages={3877–3888} }
 @article{nazarov_shenderova_brenner_2000, title={Elastic models of symmetrical < 002 > and < 011 > tilt grain boundaries in diamond}, volume={61}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.61.928}, abstractNote={~Received 3 May 1999! The disclination-structural units model ~DSUM!, which was previously applied to grain boundaries in metals and a limited number of structures in the diamond cubic lattice, is extended to treat more complicated metastable structures of ^001& and ^011& symmetric tilt boundaries in diamond. These structures are described in terms of flat and faceted disclination dipole walls and screw dislocation dipole walls, with the energies of these defects calculated from anisotropic elasticity theory. Disclination-dislocation models are constructed for ^001& tilt boundaries in the complete misorientation range and for ^011& tilt boundaries in the range 0 <u<70.5°, and the energy versus misorientation curves are calculated using input structures and energies of key grain boundaries obtained from atomistic modeling. Quantitative agreement with atomistic predictions is obtained for the most stable grain-boundary structures, while predictions of the DSUM for higher-energy metastable structures are qualitatively consistent with atomic studies.}, number={2}, journal={PHYSICAL REVIEW B}, author={Nazarov, AA and Shenderova, OA and Brenner, DW}, year={2000}, month={Jan}, pages={928–936} }
 @article{shenderova_mewkill_brenner_2000, title={Nanoindentation as a probe of nanoscale residual stresses: Atomistic simulation results}, volume={25}, ISSN={["0892-7022"]}, DOI={10.1080/08927020008044114}, abstractNote={Abstract Results from two sets of molecular dynamics simulations are reported. In the first set of simulations a nanoscale tip was used to indent single-crystal gold lattices subjected to external strains. These were carried out to explore possible relationships between nanoindentation curves and elastic properties of uniformly strained films. The changes in the slope of the loading curves reflect the stress state of the sample. In the second set of simulations the use of shallow nanoindentation for mapping nonuniform residual surface stress near a dislocation intersecting a surface was tested. Correlation between the maximum force on the tip and the initial local stresses at the point of indentation were observed. Preliminary atomistic simulations indicate that atomic-force microscopy can be used as a nondestructive, nanoscale probe of the surface stress distributions.}, number={1-2}, journal={MOLECULAR SIMULATION}, author={Shenderova, O and Mewkill, J and Brenner, DW}, year={2000}, pages={81-+} }
 @article{tragler_srinivasan_shenderova_mcclauren_brenner_2000, title={Novel simulation tools for materials engineering education}, volume={25}, ISSN={["0892-7022"]}, DOI={10.1080/08927020008044116}, abstractNote={Abstract A novel simulation interface is being developed as an educational tool to help students better understand fundamentals of materials science. This interface makes use of virtual reality (VR) technology consisting of PC-based graphics and a force-feedback haptic device. Visualization of atomistic processes with simultaneous tactile sensation via the haptic provides a powerful method for understanding complex phenomena that are otherwise difficult to comprehend. Modules are described that allow students to interactively explore interatomic bonding and single-atom diffusion through materials.}, number={1-2}, journal={MOLECULAR SIMULATION}, author={Tragler, A and Srinivasan, L and Shenderova, O and McClauren, M and Brenner, DW}, year={2000}, pages={121–130} }
 @article{nazarov_shenderova_brenner_2000, title={On the disclination-structural unit model of grain boundaries}, volume={281}, ISSN={["0921-5093"]}, DOI={10.1016/s0921-5093(99)00727-3}, abstractNote={The relation between two elastic continuum approaches to grain boundary structure, the dislocation and disclination models, is discussed. It is shown that the disclination model has two advantages: a well-behaved expression for the elastic energy of disclination dipole walls, which describes the elastic energy over a wide interval of misorientations, and a continuous misorientation angle dependence of the elastic energy of grain boundaries in an interval between two delimiting boundaries. The elastic energy of the most general, faceted disclination wall is calculated. For cases in which both the energies of delimiting boundaries and elastic constants are available from atomic simulations (〈001〉 and 〈111〉 tilt boundaries in copper and 〈001〉 and 〈011〉 tilt boundaries in diamond) quantitative agreement between the disclination model and simulation results is obtained.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Nazarov, AA and Shenderova, OA and Brenner, DW}, year={2000}, month={Apr}, pages={148–155} }
 @article{shenderova_brenner_omeltchenko_su_yang_nazarov_2000, title={Properties of polycrystalline diamond: Multiscale modeling approach}, volume={24}, ISSN={["1029-0435"]}, DOI={10.1080/08927020008024196}, abstractNote={Abstract Two modeling techniques to characterize fracture behavior of polycrystalline diamond films are discussed. The first technique is a multiscale modeling method in which first-principles local density approximation calculations on selected structures are combined with an analytic mesoscale model to obtain energies and cleavage fracture energies for symmetric ⟨001⟩ tilt grain boundaries (GBs) over the entire misorientation range. The second technique is large-scale atomistic simulation of the dynamics of failure in notched polycrystalline diamond samples under an applied strain. Electronic characteristics of selected ⟨001⟩ symmetrical tilt GBs calculated with a semiempirical tight-binding Hamiltonian are also presented, and the possible role of graphitic defects on field emission from polycrystalline diamond is briefly discussed.}, number={1-3}, journal={MOLECULAR SIMULATION}, author={Shenderova, OA and Brenner, DW and Omeltchenko, A and Su, X and Yang, LH and Nazarov, A}, year={2000}, pages={197–207} }
 @article{shenderova_brenner_1999, title={Atomistic simulations of structures and mechanical properties of < 011 > tilt grain boundaries and their triple junctions in diamond}, volume={60}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.60.7053}, abstractNote={Atomic structures, energies, and stress distributions of symmetrical ^011& tilt grain boundaries~GB’s! and selected GB triple junctions~TJ’s! in diamond as well as a multiply twinned diamond particle have been calculated using an analytic bond order potential function. In general, energies of ^011& tilt GB’s are about 1 J/m lower than those for̂001& tilt GB’s calculated with the same analytic potential. Energy ordering for two models of theS53(21̄1) GB obtained with the present bond-order potential is consistent with results from a tight-binding model. Atomic structures of selected triple junctions of ^011& grain boundaries are modeled and atomic reconstructions within TJ cores that eliminate dangling bonds are suggested. Despite a perfect geometrical matching of structural units within the triple junction cores, excess energies and stresses exist in the vicinity of these structures. Characteristics of atomic stress distributions in multiply twinned particles agree with predictions of continuum disclination theory. @S0163-1829 ~99!09333-9#}, number={10}, journal={PHYSICAL REVIEW B}, author={Shenderova, OA and Brenner, DW}, year={1999}, month={Sep}, pages={7053–7061} }
 @article{shenderova_brenner_yang_1999, title={Atomistic simulations of structures and mechanical properties of polycrystalline diamond: Symmetrical < 001 > tilt grain boundaries}, volume={60}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.60.7043}, abstractNote={Atomic structures and energies of symmetrical {l_angle}001{r_angle} tilt grain boundaries (GB{close_quote}s) in diamond have been calculated over a wide range of misorientation angle using a many-body analytic potential, and for some selected short-period grain boundaries with tight-binding and first-principles density-functional methods. The grain boundary energies from the tight-binding and first-principles methods are about 75{percent} of those calculated with the analytic bond-order potential. The energy rankings of the GB{close_quote}s calculated with the empirical potential, however, are similar to that calculated from the tight-binding and the density functional approaches. Atomic-level energy and stress distributions calculated with the bond-order potential reveal relations between local interface reconstruction and the extent and value of hydrostatic and shear stresses. From the calculated local volume strain and hydrostatic stress fields, the atomic bulk moduli are evaluated, and zones of different elastic behavior in the vicinity of the interface are defined. {copyright} {ital 1999} {ital The American Physical Society}}, number={10}, journal={PHYSICAL REVIEW B}, author={Shenderova, OA and Brenner, DW and Yang, LH}, year={1999}, month={Sep}, pages={7043–7052} }
 @article{sinnott_shenderova_white_brenner_1999, title={Mechanical properties of nanotubule fibers and composites determined from theoretical calculations and simulations (vol 36, pg 1, 1998)}, volume={37}, number={2}, journal={Carbon}, author={Sinnott, S. B. and Shenderova, O. A. and White, C. T. and Brenner, D. W.}, year={1999}, pages={347} }
 @article{sinnott_shenderova_white_brenner_1998, title={Mechanical properties of nanotubule fibers and composites determined from theoretical calculations and simulations}, volume={36}, ISSN={["0008-6223"]}, DOI={10.1016/s0008-6223(97)00144-9}, abstractNote={Theoretical Young's moduli have been estimated for carbon fibers composed of single-walled fullerene nanotubules aligned in the direction of the tubule axis. In the limit of infinitely long tubules, the fibers can have a Young's modulus comparable to that of diamond. Exploiting this property of nanotubule fibers, we investigate a new carbon composite composed of layered nanotubule fibers and diamond. Such a composite is found to be a high-modulus, low-density material that is quite stable to shear and other distortions.}, number={1-2}, journal={CARBON}, author={Sinnott, SB and Shenderova, OA and White, CT and Brenner, DW}, year={1998}, pages={1–9} }
 @article{shenderova_brenner_nazarov_romanov_yang_1998, title={Multiscale modeling approach for calculating grain-boundary energies from first principles}, volume={57}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.57.r3181}, abstractNote={A multiscale modeling approach is proposed for calculating energies of tilt-grain boundaries in covalent materials from first principles over an entire misorientation range for given tilt axes. The method uses energies from density-functional calculations for a few key structures as input into a disclination structural-units model. This approach is demonstrated by calculating energies of {l_angle}001{r_angle}-symmetrical tilt-grain boundaries in diamond. {copyright} {ital 1998} {ital The American Physical Society}}, number={6}, journal={PHYSICAL REVIEW B}, author={Shenderova, OA and Brenner, DW and Nazarov, AA and Romanov, AE and Yang, LH}, year={1998}, month={Feb}, pages={R3181–R3184} }
 @article{brenner_schall_mewkill_shenderova_sinnott_1998, title={Virtual design and analysis of nanometer-scale sensor and device components}, volume={51}, number={1998}, journal={Journal of the British Interplanetary Society}, author={Brenner, D. W. and Schall, J. D. and Mewkill, J. P and Shenderova, O. A. and Sinnott, S. B.}, year={1998}, pages={137–144} }
 @article{sinnott_colton_white_shenderova_brenner_harrison_1997, title={Atomistic simulations of the nanometer-scale indentation of amorphous-carbon thin films}, volume={15}, ISSN={["0734-2101"]}, DOI={10.1116/1.580782}, abstractNote={Molecular dynamics simulations are used to examine the nanometer-scale indentation of a thin film of amorphous carbon with a nonrigid sp3 bonded carbon tip. The simulations show in detail the atomic-scale mechanism of the indentation process and compare the bonding character of the film before and after indentation. The computationally determined elastic modulus of the amorphous-carbon film is found to be 243 GPa, in good agreement with experiment.}, number={3}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS}, author={Sinnott, SB and Colton, RJ and White, CT and Shenderova, OA and Brenner, DW and Harrison, JA}, year={1997}, pages={936–940} }