@article{leonard_markevich_peaker_hamilton_yousseff_rozgonyi_2014, title={Molybdenum nano-precipitates in silicon: A TEM and DLTS study}, volume={251}, number={11}, journal={Physica Status Solidi. B, Basic Solid State Physics}, author={Leonard, S. and Markevich, V. P. and Peaker, A. R. and Hamilton, B. and Yousseff, K. and Rozgonyi, G.}, year={2014}, pages={2201–2204} }
 @article{zheng_jagannadham_youssef_2014, title={Thermal conductivity of exfoliated p-type bismuth antimony telluride}, volume={43}, number={2}, journal={Journal of Electronic Materials}, author={Zheng, H. and Jagannadham, K. and Youssef, K.}, year={2014}, pages={320–328} }
 @article{youssef_shi_radue_good_rozgonyi_2013, title={Effect of oxygen and associated residual stresses on the mechanical properties of high growth rate Czochralski silicon}, volume={113}, number={13}, journal={Journal of Applied Physics}, author={Youssef, K. and Shi, M. and Radue, C. and Good, E. and Rozgonyi, G.}, year={2013} }
 @article{shi_youssef_rozgonyi_2013, title={Fracture strength of photovoltaic silicon wafers evaluated using a controlled flaw method}, volume={15}, number={8}, journal={Advanced Engineering Materials}, author={Shi, M. R. and Youssef, K. and Rozgonyi, G. A.}, year={2013}, pages={756–760} }
 @article{zdanowicz_dow_scattergood_youssef_2013, title={Nanostructure fabrication on germanium and silicon by nanocoining imprint technique}, volume={37}, ISSN={["1873-2372"]}, DOI={10.1016/j.precisioneng.2013.05.004}, abstractNote={Germanium (Ge) and silicon (Si) material response to indentation with a nanostructured die is investigated. A diamond die attached to a high speed actuator previously used to create large arrays of nanofeatures on metallic surfaces was used to create nanofeatures on Ge and Si samples. The pressure induced transformation of Ge and Si from a diamond cubic brittle phase to a more ductile beta-tin metallic phase due to the nanofeatures on the die was investigated. Results using the dynamic nanocoining method showed chip-like deformation around the individual nanofeatures indicative of the beta-tin phase transformation at the nanofeature level. Micro-Raman measurements confirmed the metallic transition from evidence including metastable and amorphous phases after indentation. Indents created using a common linear indentation method exhibited similar behavior. The Si nanofeature deformation was compared to electroless (EL) nickel and the deformation differed as dictated by the mechanism of material flow. Although not observed in Si, fracture occurred in some Ge indents at higher loads as a result of the lower fracture toughness compared to Si.}, number={4}, journal={PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY}, author={Zdanowicz, Erik and Dow, Thomas A. and Scattergood, Ronald O. and Youssef, Khaled}, year={2013}, month={Oct}, pages={871–879} }
 @article{bahmanpour_youssef_horky_setman_atwater_zehetbauer_scattergood_koch_2012, title={Deformation twins and related softening behavior in nanocrystalline Cu-30% Zn alloy}, volume={60}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2012.02.036}, abstractNote={Nanocrystalline Cu–30% Zn samples were produced by high energy ball milling at 77 K and room temperature. Cryomilled flakes were further processed by ultrahigh strain high pressure torsion (HPT) or room temperature milling to produce bulk artifact-free samples. Deformation-induced grain growth and a reduction in twin probability were observed in HPT consolidated samples. Investigations of the mechanical properties by hardness measurements and tensile tests revealed that at small grain sizes of less than ∼35 nm Cu–30% Zn deviates from the classical Hall–Petch relation and the strength of nanocrsytalline Cu–30% Zn is comparable with that of nanocrystalline pure copper. High resolution transmission electron microscopy studies show a high density of finely spaced deformation nanotwins, formed due to the low stacking fault energy of 14 mJ m–2 and low temperature severe plastic deformation. Possible softening mechanisms proposed in the literature for nanotwin copper are addressed and the twin-related softening behavior in nanotwinned Cu is extended to the Cu–30% Zn alloy based on detwinning mechanisms.}, number={8}, journal={ACTA MATERIALIA}, author={Bahmanpour, Hamed and Youssef, Khaled M. and Horky, Jelena and Setman, Daria and Atwater, Mark A. and Zehetbauer, Michael J. and Scattergood, Ronald O. and Koch, Carl C.}, year={2012}, month={May}, pages={3340–3349} }
 @article{kulshreshtha_youssef_rozgonyi_2012, title={Nano-indentation: A tool to investigate crack propagation related phase transitions in PV silicon}, volume={96}, number={1}, journal={Solar Energy Materials and Solar Cells}, author={Kulshreshtha, P. K. and Youssef, K. M. and Rozgonyi, G.}, year={2012}, pages={166–172} }
 @article{kulshreshtha_yoon_youssef_good_rozgonyi_2012, title={Oxygen precipitation related stress-modified crack propagation in high growth rate Czochralski silicon wafers}, volume={159}, number={2}, journal={Journal of the Electrochemical Society}, author={Kulshreshtha, P. K. and Yoon, Y. and Youssef, K. M. and Good, E. A. and Rozgonyi, G.}, year={2012}, pages={H125–129} }
 @article{roy_atwater_youssef_ledford_scattergood_koch_2013, title={Studies on thermal stability, mechanical and electrical properties of nano crystalline Cu99.5Zr0.5 alloy}, volume={558}, ISSN={["0925-8388"]}, DOI={10.1016/j.jallcom.2012.11.004}, abstractNote={Cryogenic high energy ball milling was used to synthesize nanocrystalline Cu and Cu99.5Zr0.5 alloys by mechanical alloying and consolidation by hot pressing at 550 °C temperature. The grain size stability of nanocrystalline Cu is improved by the Zr addition. Microstructural characterization using X-ray diffraction and transmission electron microscopy provided evidence for the formation of a Cu–Zr alloy solid solution with nanocrystalline size after hot pressing. The alloy exhibited a higher hardness (3.31 GPa), and shear strength (550 MPa) than nano-crystalline pure Cu however, the electrical resistivity is increased in the alloy.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Roy, Debdas and Atwater, Mark A. and Youssef, Khaled and Ledford, John Christopher and Scattergood, Ronald O. and Koch, Carl C.}, year={2013}, month={May}, pages={44–49} }
 @article{youssef_yu_seacrist_rozgonyi_2012, title={Understanding the effect of impurities and grain boundaries on mechanical behavior of Si via nanoindentation of (110)/(100) direct Si bonded wafers}, volume={27}, number={1}, journal={Journal of Materials Research}, author={Youssef, K. and Yu, X. G. and Seacrist, M. and Rozgonyi, G.}, year={2012}, pages={349–355} }
 @article{bahmanpour_kauffmann_khoshkhoo_youssef_mula_freudenberger_eckert_scattergood_koch_2011, title={Effect of stacking fault energy on deformation behavior of cryo-rolled copper and copper alloys}, volume={529}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2011.09.022}, abstractNote={Abstract Pure copper and Cu–12.1 at.%Al–4.1 at.%Zn alloy were subjected to rolling in liquid nitrogen. TEM studies showed that dynamic recovery during the deformation process was effectively suppressed and hence microstructures with dislocation substructure and deformation twins were formed. Mechanical properties were assessed via microtensile testing that shows improved yield strength, 520 ± 20 MPa, and ductility, 22%, in the case of pure copper. Alloying with Al and Zn results in reduction in stacking fault energy (SFE) which can contribute to enhanced strength and good ductility. Physical activation volume obtained via stress relaxation tests is 26 b 3 , and 8 b 3 for pure copper, and Cu–12.1 at.%Al–4.1 at.%Zn, respectively. The effect of SFE on work hardening rate of samples is discussed. Although twinning is observed in the alloy, it is concluded that network dislocation strengthening plays the major role in determining the mechanical properties.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Bahmanpour, H. and Kauffmann, A. and Khoshkhoo, M. S. and Youssef, K. M. and Mula, S. and Freudenberger, J. and Eckert, J. and Scattergood, R. O. and Koch, C. C.}, year={2011}, month={Nov}, pages={230–236} }
 @article{youssef_sakaliyska_bahmanpour_scattergood_koch_2011, title={Effect of stacking fault energy on mechanical behavior of bulk nanocrystalline Cu and Cu alloys}, volume={59}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2011.05.052}, abstractNote={Twinning and dislocation slip are two major and competing modes of plastic deformation in metals and alloys. In addition to controlling the dislocation substructure in coarse grained materials, stacking fault energy (SFE) also affects the propensity to form deformation twins. However, the influence of SFE has not been fully explored in nanocrystalline materials. Here the role of SFE in deformation twinning and work hardening was systematically studied in bulk artifact-free, nanocrystalline (nc) Cu (SFE 55 mJ m−2), and a nc Cu–12.1 at.% Al–4.1 at.% Zn alloy (SFE 7 mJ m−2). The nc Cu (23 nm) and nc Cu alloy (22 nm) were synthesized using in situ consolidation during cryo and room temperature milling. Both materials showed ultra-high tensile strength, significant strain hardening, and good ductility. The nc Cu alloy exhibits a higher yield strength and lower uniform elongation (1067 ± 20 MPa, 6.5%) than that of nc Cu (790 ± 12 MPa, 14%). The SFE variation played a significant role in strengthening the nc Cu alloy. High resolution transmission electron microscopy analyses revealed that the low SFE of the nc Cu alloy alters the deformation mechanism from a dislocation-controlled deformation, which allows for the higher strain hardening observed in the nc Cu, to a twin-controlled deformation.}, number={14}, journal={ACTA MATERIALIA}, author={Youssef, Khaled and Sakaliyska, Miroslava and Bahmanpour, Hamed and Scattergood, Ronald and Koch, Carl}, year={2011}, month={Aug}, pages={5758–5764} }
 @article{youssef_wang_liao_mathaudhu_kecskes_zhu_koch_2011, title={High hardness in a nanocrystalline Mg97Y2Zn1 alloy}, volume={528}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2011.06.017}, abstractNote={A nanocrystalline Mg97Y2Zn1 alloy was prepared with an average grain size of 21 nm by mechanical alloying of elemental powders. The structure of the alloy was characterized by X-ray diffraction and transmission electron microscopy. The hardness of the alloy as-milled for 8 h at room temperature was 2.1 GPa. After compaction and annealing at 573 K, the average grain size slightly increases to 28 nm with an increase in hardness to 2.4 GPa. These are the highest values for hardness yet reported for a crystalline Mg-based (>95% Mg) alloy. Possible factors leading to this high strength are discussed.}, number={25-26}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Youssef, K. M. and Wang, Y. B. and Liao, X. Z. and Mathaudhu, S. N. and Kecskes, L. J. and Zhu, Y. T. and Koch, C. C.}, year={2011}, month={Sep}, pages={7494–7499} }
 @article{bahmanpour_youssef_scattergood_koch_2011, title={Mechanical behavior of bulk nanocrystalline copper alloys produced by high energy ball milling}, volume={46}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-011-5312-3}, number={19}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Bahmanpour, H. and Youssef, K. M. and Scattergood, R. O. and Koch, C. C.}, year={2011}, month={Oct}, pages={6316–6322} }
 @article{wu_youssef_koch_mathaudhu_kecskes_zhu_2011, title={Deformation twinning in a nanocrystalline hcp Mg alloy}, volume={64}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2010.10.024}, abstractNote={Nanocrystalline (nc) hexagonal close-packed (hcp) metals are rarely observed to deform by twinning, which is contrary to face-centered cubic metals. Here we report that, after alloying Mg with 10 at.% Ti, deformation twins are observed in an nc Mg–Ti alloy processed by mechanical attrition. The formation of deformation twins is attributed to the alloying effect, which may change the energy path for twinning. These results point to a promising approach to design nc hcp alloys for superior mechanical properties.}, number={3}, journal={SCRIPTA MATERIALIA}, author={Wu, X. L. and Youssef, K. M. and Koch, C. C. and Mathaudhu, S. N. and Kecskes, L. J. and Zhu, Y. T.}, year={2011}, month={Feb}, pages={213–216} }
 @article{beltran_amatya_youssef_jones_callahan_skaggs_nettles_2010, title={Impacts of Fertilization on Water Quality of a Drained Pine Plantation: A Worst Case Scenario}, volume={39}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2008.0506}, abstractNote={Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31‐yr) and one young (8‐yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature‐thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (α = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature‐thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature‐thinned watershed.}, number={1}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Beltran, Bray J. and Amatya, Devendra M. and Youssef, Mohamed and Jones, Martin and Callahan, Timothy J. and Skaggs, R. Wayne and Nettles, Jami E.}, year={2010}, pages={293–303} }
 @article{koch_scattergood_youssef_chan_zhu_2010, title={Nanostructured materials by mechanical alloying: new results on property enhancement}, volume={45}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-010-4252-7}, number={17}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Koch, Carl C. and Scattergood, Ronald O. and Youssef, Khaled M. and Chan, Ethan and Zhu, Yuntian T.}, year={2010}, month={Sep}, pages={4725–4732} }
 @article{gollapudi_rajulapati_charit_youssef_koch_scattergood_murty_2010, title={Understanding creep in nanocrystalline materials}, volume={63}, ISSN={["0975-1645"]}, DOI={10.1007/s12666-010-0050-9}, number={2-3}, journal={TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS}, author={Gollapudi, S. and Rajulapati, K. V. and Charit, I. and Youssef, K. M. and Koch, C. C. and Scattergood, R. O. and Murty, K. L.}, year={2010}, month={Apr}, pages={373–378} }
 @article{yu_lu_youssef_rozgonyi_2009, title={Proximity gettering of Cu at a (110)/(001) grain boundary interface formed by direct silicon bonding}, volume={94}, number={22}, journal={Applied Physics Letters}, author={Yu, X. and Lu, J. and Youssef, K. and Rozgonyi, G.}, year={2009} }
 @article{youssef_koch_fedkiw_2008, title={Influence of pulse plating parameters on the synthesis and preferred orientation of nanocrystalline zinc from zinc sulfate electrolytes}, volume={54}, ISSN={["1873-3859"]}, DOI={10.1016/j.electacta.2008.07.048}, abstractNote={The influence of pulse electrodeposition parameters (current on-time Ton, current off-time Toff, and pulse current density Jp) was investigated on the surface morphology and grain size of zinc electrodeposited from a sulfate bath containing polyacrylamide and thiourea additives. The grain size and surface morphology of zinc deposits were studied by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), and the preferred orientation of the deposits was studied by X-ray diffraction. At constant current off-time and pulse current density, the grain size decreased asymptotically with increasing current on-time. In contrast, increase in the current off-time at constant current on-time and pulse current density resulted in grain growth. A progressive decrease of the grain size was observed with increasing pulse current density at constant current on-time and off-time. Nanocrystalline zinc with an average grain size of 38 nm was obtained at a pulse current density of 1200 mA/cm2. The crystallographic orientations developed were correlated with the change in the cathodic overpotential, the angle between the preferred oriented plane and the lowest energy of formation plane (0 0 0 2), and the pulse electrodeposition parameters.}, number={2}, journal={ELECTROCHIMICA ACTA}, author={Youssef, K. M. and Koch, C. C. and Fedkiw, P. S.}, year={2008}, month={Dec}, pages={677–683} }
 @article{koch_youssef_scattergood_murty_2005, title={Breakthroughs in optimization of mechanical properties of nanostructured metals and alloys}, volume={7}, DOI={10.1002/adern.200500094}, number={9}, journal={Advanced Engineering Materials}, author={Koch, C. C. and Youssef, K. M. and Scattergood, R. O. and Murty, K. L.}, year={2005}, pages={787–794} }
 @article{zhang_raynova_koch_scattergood_youssef_2005, title={Consolidation of a Cu-2.5 vol.% Al2O3 powder using high energy mechanical milling}, volume={410}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2005.08.109}, abstractNote={Abstract In situ consolidation of a Cu–2.5 vol.% Al 2 O 3 powder by high energy ball milling has been studied by examining changes of size, morphology, macrostructure and microstructure of the powder particles, lumps, and balls formed with increasing milling time under different conditions. This study clearly demonstrates that the consolidation of the Cu–2.5 vol.% Al 2 O 3 powder by high energy ball milling is accomplished initially by coalescence of powder particles through cold welding which leads to formation of lumps, then by cold welding and re-shaping of the lumps into small balls, and finally by cold welding of small balls into larger balls. The maximum diameter of the large balls is comparable with the diameter of the milling balls used as a milling medium. The two types of defects in the consolidated lumps and balls in the large balls, concentrated voids and crack-like voids, show that the material undergoes a large amount of plastic flow during the process of consolidation. The consolidation of the Cu–2.5 vol.% Al 2 O 3 powder can also been achieved by a combination of cryomilling and room temperature milling, but the consolidation process is slower due to increased hardness of the powder particles. The study also shows that the Al 2 O 3 fine particles are incorporated into the Cu matrix forming a composite structure when the lumps are formed, and the large balls exhibit a nanostructure with grain sizes smaller than 100 nm.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Zhang, DL and Raynova, S and Koch, CC and Scattergood, RO and Youssef, KM}, year={2005}, month={Nov}, pages={375–380} }
 @article{youssef_scattergood_murty_koch_2006, title={Nanocrystalline Al-Mg alloy with ultrahigh strength and good ductility}, volume={54}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2005.09.028}, abstractNote={A bulk nanocrystalline Al–5%Mg alloy was synthesized by an in situ consolidation mechanical alloying technique. The mechanical behavior of this alloy was investigated by hardness and tensile tests, which revealed it has four times the strength of a conventional Al-5083 alloy along with good ductility (8.5% elongation). The microstructure was investigated by X-ray diffraction and transmission electron microscopy, and the fracture surface by scanning electron microscopy.}, number={2}, journal={SCRIPTA MATERIALIA}, author={Youssef, KM and Scattergood, RO and Murty, KL and Koch, CC}, year={2006}, month={Jan}, pages={251–256} }
 @article{cheng_ma_wang_kecskes_youssef_koch_trociewitz_han_2005, title={Tensile properties of in situ consolidated nanocrystalline Cu}, volume={53}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2004.12.005}, abstractNote={We have prepared Cu powders with nanocrystalline grain sizes via ball milling at liquid nitrogen temperature. An in situ consolidation technique was used to produce fully dense nanocrystalline Cu samples centimeters in lateral dimensions and about one millimeter in thickness. We report a much improved combination of tensile strength and ductility, over the tensile properties of other nanocrystalline Cu materials documented in the literature. We also demonstrate the elevated strain rate sensitivity and strong temperature dependence of the flow stress and explain the results in terms of the thermally activated deformation mechanisms operative in the nanocrystalline grains. The nearly perfectly plastic behavior and shear localization observed are discussed and compared with the strain hardening behavior and deformation modes known for other nanocrystalline metals.}, number={5}, journal={ACTA MATERIALIA}, author={Cheng, S and Ma, E and Wang, YM and Kecskes, LJ and Youssef, KM and Koch, CC and Trociewitz, UP and Han, K}, year={2005}, month={Mar}, pages={1521–1533} }
 @article{youssef_scattergood_murty_horton_koch_2005, title={Ultrahigh strength and high ductility of bulk nanocrystalline copper}, volume={87}, ISSN={["1077-3118"]}, DOI={10.1063/1.2034122}, abstractNote={We have synthesized artifact-free bulk nanocrystalline copper samples with a narrow grain size distribution (mean grain size of 23nm) that exhibited tensile yield strength about 11 times higher than that of conventional coarse-grained copper, while retaining a 14% uniform tensile elongation. In situ dynamic straining transmission electron microscope observations of the nanocrystalline copper are also reported, which showed individual dislocation motion and dislocation pile-ups. This suggests a dislocation-controlled deformation mechanism that allows for the high strain hardening observed. Trapped dislocations are observed in the individual nanograins.}, number={9}, journal={APPLIED PHYSICS LETTERS}, author={Youssef, KM and Scattergood, RO and Murty, KL and Horton, JA and Koch, CC}, year={2005}, month={Aug} }
 @article{youssef_koch_fedkiw_2004, title={Influence of additives and pulse electrodeposition parameters on production of nanocrystalline zinc from zinc chloride electrolytes}, volume={151}, ISSN={["1945-7111"]}, DOI={10.1149/1.1636739}, abstractNote={Pulse electrodeposition was used to produce nanocrystalline zinc from an aqueous zinc chloride electrolyte with polyacrylamide and thiourea as additives. The influence of additive concentration and pulse electrodeposition parameters, namely, current-on time, current-off time, and peak current density on the grain size, surface morphology, and preferred orientation was investigated. The grain size and surface morphology of zinc deposits were studied by scanning electron microscopy and field emission scanning electron microscopy. The preferred orientation of zinc deposits was studied by X-ray diffraction. The optimum concentrations of polyacrylamide and thiourea in the bath that give the finest grains were 0.7 and 0.05 g/L, respectively. At constant current-off time and peak current density, the grain size decreased asymptotically with increasing current-on time. An increase in the current-off time at constant current-on time and peak current density resulted in grain growth. A progressive decrease of the grain size was observed with increasing peak current density at constant current-on and -off time. Nanocrystalline zinc with an average grain size of 50 nm was obtained at a peak current density of 1000 mA/cm 2 . The crystal orientations developed were correlated to the variation in the cathode overpotential accompanied with changing the electrodeposition parameters. A (1013) preferred orientation was developed at low overpotential while higher overpotential developed a dual (1122) (1010) orientation.}, number={2}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Youssef, KMS and Koch, CC and Fedkiw, PS}, year={2004}, month={Feb}, pages={C103–C111} }
 @article{youssef_scattergood_murty_koch_2004, title={Ultratough nanocrystalline copper with a narrow grain size distribution}, volume={85}, ISSN={["1077-3118"]}, DOI={10.1063/1.1779342}, abstractNote={We report a unique way of using mechanical milling/in situ consolidation at both liquid-nitrogen and room temperature to produce artifact-free nanocrystalline Cu(23nm) with a narrow grain size distribution. This nanocrystalline Cu exhibits an extraordinarily high yield strength (770MPa), as predicted from a Hall–Petch extrapolation, along with good ductility (comparable with ∼30% uniform tensile elongation). Possible factors leading to this excellent optimization of strength and ductility are discussed.}, number={6}, journal={APPLIED PHYSICS LETTERS}, author={Youssef, KM and Scattergood, RO and Murty, KL and Koch, CC}, year={2004}, month={Aug}, pages={929–931} }
 @article{youssef_koch_fedkiw_2004, title={Improved corrosion behavior of nanocrystalline zinc produced by pulse-current electrodeposition}, volume={46}, ISSN={["1879-0496"]}, DOI={10.1016/S0010-938X(03)00142-2}, abstractNote={Pulse electrodeposition was used to produce nanocrystalline (nc) zinc from zinc chloride electrolyte with polyacrylamide and thiourea as additives. Field emission scanning electron microscopy (FESEM) was used to study the grain size and surface morphology of the deposits and X-ray diffraction was used to examine their preferred orientation. Corrosion behavior of the electrodeposited nc zinc in comparison with electrogalvanized (EG) steel in de-aerated 0.5 N NaOH solution was studied using potentiodynamic polarization and impedance measurements. A scanning electron microscope (SEM) was used to characterize the surface morphology of the EG steel before corrosion testing. Surface morphologies of nc zinc deposits and EG steel were also studied after potentiondynamic polarization by SEM. Nanocrystalline zinc (56 nm) with random orientation was produced. The estimated corrosion rate of nc zinc was found to be about 60% lower than that of EG steel, 90 and 229 μA/cm2, respectively. The surface morphology of corroded nc zinc was characterized by discrete etch pits, however, uniform corrosion was obtained after potentiodynamic polarization of EG steel. The passive film formed on the nc zinc surface seems to be a dominating factor for the corrosion behavior observed.}, number={1}, journal={CORROSION SCIENCE}, author={Youssef, KMS and Koch, CC and Fedkiw, PS}, year={2004}, month={Jan}, pages={51–64} }