@article{denis-rotella_esteves_walker_zhou_jones_trolier-mckinstry_2021, title={Residual Stress and Ferroelastic Domain Reorientation in Declamped {001} Pb(Zr0.3Ti0.7)O-3 Films}, volume={68}, ISSN={["1525-8955"]}, DOI={10.1109/TUFFC.2020.2987438}, abstractNote={Ferroelectric films are often constrained by their substrates and subject to scaling effects, including suppressed dielectric permittivity. In this work, the thickness dependence of intrinsic and extrinsic contributions to the dielectric properties was elucidated. A novel approach to quantitatively deconstruct the relative permittivity into three contributions (intrinsic, reversible extrinsic, and irreversible extrinsic) was developed using a combination of X-ray diffraction (XRD) and Rayleigh analysis. <italic>In situ</italic> synchrotron XRD was used to understand the influence of residual stress and substrate clamping on the domain state, ferroelastic domain reorientation, and electric field-induced strain. For tetragonal {001} textured Pb<sub>0.99</sub>(Zr<sub>0.3</sub>Ti<sub>0.7</sub>)<sub>0.98</sub>Nb<sub>0.02</sub>O<sub>3</sub> thin films clamped to an Si substrate, a thickness-dependent in-plane tensile stress developed during processing, which dictates the domain distribution over a thickness range of 0.27–<inline-formula> <tex-math notation="LaTeX">$1.11~\mu \text{m}$ </tex-math></inline-formula>. However, after the films were partially declamped from the substrate and annealed, the residual stress was alleviated. As a result, the thickness dependence of the volume fraction of <inline-formula> <tex-math notation="LaTeX">${c}$ </tex-math></inline-formula>-domains largely disappeared, and the out-of-plane lattice spacings (<inline-formula> <tex-math notation="LaTeX">${d}$ </tex-math></inline-formula>) for both <inline-formula> <tex-math notation="LaTeX">${a}$ </tex-math></inline-formula>- and <inline-formula> <tex-math notation="LaTeX">${c}$ </tex-math></inline-formula>-domains increased. The volume fraction of <inline-formula> <tex-math notation="LaTeX">${c}$ </tex-math></inline-formula>-domains was used to calculate the intrinsic relative permittivity. The reversible Rayleigh coefficient was then used to separate the intrinsic and reversible extrinsic contributions. The reversible extrinsic response accounted for ~50% of the overall relative permittivity (measured at 50 Hz and alternating current (ac) field of <inline-formula> <tex-math notation="LaTeX">$0.5\cdot {E}_{c}$ </tex-math></inline-formula>) and was thickness dependent even after poling and upon release.}, number={2}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Denis-Rotella, Lyndsey M. and Esteves, Giovanni and Walker, Julian and Zhou, Hanhan and Jones, Jacob L. and Trolier-McKinstry, Susan}, year={2021}, month={Feb}, pages={259–272} }
 @article{khazaee_sardashti_chung_sun_zhou_bergmann_dunlap-shohl_han_hill_jones_et al._2019, title={Dual-source evaporation of silver bismuth iodide films for planar junction solar cells}, volume={7}, ISSN={2050-7488 2050-7496}, url={http://dx.doi.org/10.1039/C8TA08679F}, DOI={10.1039/c8ta08679f}, abstractNote={Dual-source evaporation approach is applied to deposit AgBi2I7, AgBiI4 and Ag2BiI5 films; a planar junction AgBiI4-solar cell is demonstrated.}, number={5}, journal={Journal of Materials Chemistry A}, publisher={Royal Society of Chemistry (RSC)}, author={Khazaee, Maryam and Sardashti, Kasra and Chung, Ching-Chang and Sun, Jon-Paul and Zhou, Hanhan and Bergmann, Eric and Dunlap-Shohl, Wiley A. and Han, Qiwei and Hill, Ian G. and Jones, Jacob L. and et al.}, year={2019}, pages={2095–2105} }
 @article{khazaee_sardashti_sun_zhou_clegg_hill_jones_lupascu_mitzi_2018, title={A versatile thin-film deposition method for multidimensional semiconducting bismuth halides}, volume={30}, DOI={10.1021/acs.chemmater.8b01341}, abstractNote={Despite the significant progress in fabricating hybrid organic–inorganic lead halide perovskite solar cells, their toxicity and low stability remain as major drawbacks, thereby hindering large-scale commercialization. Given the isoelectronic nature of lead(II) and bismuth(III) ions, potentially stable and nontoxic alternatives for efficient light absorption in thin-film photovoltaic (PV) devices may be found among bismuth-based halide semiconductors. However, high-quality polycrystalline films of many of these systems have not been demonstrated. Here we present a versatile and facile two-step coevaporation approach to fabricate A3Bi2I9 (A = Cs, Rb) and AgBi2I7 polycrystalline films with smooth, pinhole-free morphology and average grain size of >200 nm. The process involves an initial two-source evaporation step (involving CsI, RbI or AgI, and BiI3 sources), followed by an annealing step under BiI3 vapor. The structural, optical, and electrical characteristics of the resulting thin films are studied by X-r...}, number={10}, journal={Chemistry of Materials}, author={Khazaee, M. and Sardashti, K. and Sun, J. P. and Zhou, H. H. and Clegg, C. and Hill, I. G. and Jones, J. L. and Lupascu, D. C. and Mitzi, D. B.}, year={2018}, pages={3538–3544} }
 @article{baure_zhou_chung_buck_stozhkova_jones_nino_2018, title={Comparison of the in- and across-plane ionic conductivity of highly oriented neodymium doped ceria thin films}, volume={147}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2017.12.057}, abstractNote={To determine the effect of grain boundaries and grain orientation on the electrical properties of solid oxide fuel cell electrolytes, a comparison of the in-plane and across-plane ionic conductivity of both strongly and poorly textured, columnar-grained doped ceria thin films was performed within equivalent temperature ranges (150–300 °C). Additionally, the in-plane conductivity of partially amorphous films, polycrystalline films with randomly oriented grains, and single crystal, epitaxial films with no grain boundaries was determined. Pulsed laser deposition permitted the growth of all these types of films and the ability to grow columnar-grained doped ceria on both conducting and insulating surfaces enabled testing of the films both in-plane and across-plane. Compared to the columnar-grained samples, partially amorphous films exhibited a lower conductivity, while epitaxial doped ceria exhibited an enhancement in conductivity of 2 orders of magnitude. Between 300 and 400 °C, the in-plane conductivity of the strongly textured film was higher than the poorly textured one. The conductivity and activation energy in-plane and across-plane for the strongly textured film was similar (2.75 × 10−5 S/cm, 0.70 eV vs. 5.50 × 10−5 S/cm, 0.68 eV at 250 °C). In contrast, for the poorly textured films, the in-plane and across-plane conductivity values differed by almost an order of magnitude (2.86 × 10−5 S/cm, 0.55 eV vs. 1.99 × 10−4 S/cm, 0.78 eV at 250 °C) suggesting that the boundaries between oriented grains were less resistive. These results further strengthen the argument that grain orientation affects ionic transport through grain boundaries.}, journal={ACTA MATERIALIA}, author={Baure, George and Zhou, Hanhan and Chung, Ching-Chang and Buck, Marissa N. and Stozhkova, Mariia A. and Jones, Jacob L. and Nino, Juan C.}, year={2018}, month={Apr}, pages={10–15} }
 @article{zhao_hou_chung_zhou_kynast_hennig_liu_li_jones_2018, title={Deconvolved intrinsic and extrinsic contributions to electrostrain in high performance, Nb-doped Pb(ZrxTi1-x)O-3 piezoceramics (0.50 <= x <= 0.56)}, volume={158}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2018.08.006}, abstractNote={Lead zirconate titanate (PZT) is the base compound for the highest performing piezoelectric compositions. When doped with Nb, PZT has superior electrostrain and piezoelectric properties. However, the origin of that electrostrain involves both intrinsic and extrinsic contributions which have been challenging to deconvolute. In the present work, we utilize high-energy, synchrotron X-ray diffraction (XRD) in combination with an area detector to measure the response of 1% Nb-doped PbZrxTi1-xO3 (PZT, 0.50 ≤ x ≤ 0.56) piezoceramics to electric fields. Using analysis involving micromechanics-based calculations and pair distribution functions (PDFs), it is found that both the intrinsic and extrinsic contributions are important for realization of high electrostrain. In the compositions nearest the morphotropic phase boundary (MPB), the relative contributions of the intrinsic response increase. The interdependence of crystal symmetry (tetragonal and rhombohedral), spontaneous strain, and the extent of non-180° domain switching are also elucidated. An orientation dependence in the field-induced lattice strain is observed and attributed to extrinsic effects, i.e., the intergranular interaction between domain switching and lattice strain. Finally, the PDFs suggest that a continuous rotation of the polarization vector occurs in the tetragonal phase samples due to piezoelectric distortion, being most obvious in the compositions near the MPB, but is not observed in the rhombohedral phase samples.}, journal={ACTA MATERIALIA}, author={Zhao, Changhao and Hou, Dong and Chung, Ching-Chang and Zhou, Hanhan and Kynast, Antje and Hennig, Eberhard and Liu, Wenfeng and Li, Shengtao and Jones, Jacob L.}, year={2018}, month={Oct}, pages={369–380} }
 @article{zhou_liu_williams_griffin_cress_rivas_rudy_polcawich_glaser_bassiri-gharb_et al._2018, title={Radiation-induced changes of vacancy-type defects in ferroelectric capacitors as revealed by Doppler broadening positron annihilation spectroscopy}, volume={124}, ISSN={["1089-7550"]}, DOI={10.1063/1.5045189}, abstractNote={Thin film ferroelectric capacitors of composition Pb(Zr0.52Ti0.48)O3 were exposed to Fe3+ radiation (1011 to 1013 ions/cm2), and the change in the defect structure was investigated by Doppler broadening positron annihilation spectroscopy and other characterization techniques. As the radiation fluence increases, a systematic drop of the S parameter of the positron annihilation photopeak is observed and attributed to an increase in the Zr- and Ti-site related vacancies relative to the Pb-sites. The results demonstrate that the radiation has a more significant influence on the Zr- and Ti-sites relative to the Pb-sites. It is also observed that the S parameter of the Mn-doped samples is higher than the undoped counterparts. Coupled with ferroelectricity measurements and X-ray diffraction, the results suggest that the Mn dopant modifies the initial structure of the material and leads to a different functional response.}, number={24}, journal={JOURNAL OF APPLIED PHYSICS}, author={Zhou, Hanhan and Liu, Ming and Williams, Samuel C. and Griffin, Lee A. and Cress, Cory D. and Rivas, Manuel and Rudy, Ryan Q. and Polcawich, Ronald G. and Glaser, Evan R. and Bassiri-Gharb, Nazanin and et al.}, year={2018}, month={Dec} }
 @article{brewer_zhou_williams_rudy_rivas_polcawich_cress_glaser_paisley_ihlefeld_et al._2017, title={Effect of microstructure on irradiated ferroelectric thin films}, volume={121}, number={24}, journal={Journal of Applied Physics}, author={Brewer, S. J. and Zhou, H. H. and Williams, S. C. and Rudy, R. Q. and Rivas, M. and Polcawich, R. G. and Cress, C. D. and Glaser, E. R. and Paisley, E. A. and Ihlefeld, J. F. and et al.}, year={2017} }
 @article{baure_zhou_chung_stozhkova_jones_nino_2017, title={Grain orientation effects on the ionic conductivity of neodymia doped ceria thin films}, volume={133}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2017.05.030}, abstractNote={It is generally accepted that grain boundaries in the path of transport are detrimental to ionic conductivity. To delve deeper into the connection between grain boundaries and ionic transport, the relative orientations of the grains were determined using the transmission Kikuchi diffraction technique. Nanocrystalline (grain size ∼ 40 nm) neodymia doped ceria thin films grown via pulsed laser deposition amplify the effect of these intrinsic interfaces. In addition, this deposition technique allowed the growth of partially amorphous and columnar grained films. Further, the strength of the texture in the columnar grained films was modified by changing substrates. The in-plane impedance measurements were able to isolate the response of the film from the response of the electrode interface and confirmed the majority carriers were oxygen vacancies at low temperatures. The anionic conductivity improved as the strength of the texture in the films increased. The conductivity of the strongly textured films was 2 orders of magnitude higher than the conductivity of the randomly oriented ones between 300 and 400 °C. Also, the in-plane conductivity per grain was more than 3 orders of magnitude higher in the strongly textured film than in the poorly textured one indicating conductivity is not dependent on grain boundary density. IV measurements revealed that grain boundaries posed a potential barrier to anions in the poorly textured and randomly oriented films, but not in the strongly textured samples. The type of grain boundary was deemed a contributing factor. Boundaries between more misaligned grains were more resistive decreasing the total conductivity.}, journal={ACTA MATERIALIA}, author={Baure, George and Zhou, Hanhan and Chung, Ching-Chang and Stozhkova, Mariia A. and Jones, Jacob L. and Nino, Juan C.}, year={2017}, month={Jul}, pages={81–89} }
 @article{brewer_cress_williams_zhou_rivas_rudy_polcawich_glaser_jones_bassiri-gharb_2017, title={Phenomenological model for defect interactions in irradiated functional materials}, volume={7}, journal={Scientific Reports}, author={Brewer, S. J. and Cress, C. D. and Williams, S. C. and Zhou, H. H. and Rivas, M. and Rudy, R. Q. and Polcawich, R. G. and Glaser, E. R. and Jones, J. L. and Bassiri-Gharb, N.}, year={2017} }
 @article{hou_usher_zhou_raengthon_triamnak_cann_forrester_jones_2017, title={Temperature-induced local and average structural changes in BaTiO3-xBi(Zn1/2Ti1/2)O-3 solid solutions: The origin of high temperature dielectric permittivity}, volume={122}, number={6}, journal={Journal of Applied Physics}, author={Hou, D. and Usher, T. M. and Zhou, H. H. and Raengthon, N. and Triamnak, N. and Cann, D. P. and Forrester, J. S. and Jones, J. L.}, year={2017} }