@article{zhao_prosandeev_bellaiche_li_zhang_li_jones_2023, title={Bridging the gap between the short-range to long-range structural descriptions of the lead magnesium niobate relaxor}, volume={258}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2023.119171}, abstractNote={The structure-property relationships on different length scales and their connections to the macroscopic piezoelectric and dielectric properties are one of the most fascinating topics of relaxor ferroelectrics and need to be further explored. Here, we provide structural insights into the gap between the short-range structure and the long-range structure of the classical relaxor ferroelectric lead magnesium niobate (PMN) using a combination of theoretical simulations and pair distribution function (PDF) analysis. Our study shows that PMN exhibits a disordered low-symmetry structure at the smallest length scale (1–10 Å) and a cubic crystallographic average structure at large length scale. A rhombohedral phase is observed at the intermediate length scale (∼ 20–70 Å), resulting from chemical ordered regions with the ordered local electric field and associated quasi-correlated Pb displacements. Our work advances the understanding of the structures of relaxor ferroelectrics at different length scales and the relationships among them.}, journal={ACTA MATERIALIA}, author={Zhao, Changhao and Prosandeev, Sergey and Bellaiche, Laurent and Li, Fei and Zhang, Shujun and Li, Shengtao and Jones, Jacob L.}, year={2023}, month={Oct} }
 @article{jiang_zhao_metz_jothi_kavey_reven_lindner-d'addario_jones_caruntu_page_2022, title={Temperature dependent local structure coherence of surface-modified BaTiO3 nanocubes}, ISSN={["2050-7534"]}, DOI={10.1039/d2tc00477a}, abstractNote={BaTiO3 nanocubes capped by polar tetrafluoroborate (BF4−) ligands are shown to have enhanced ferroelectric order and undergo sharper ferroelectric to paraelectric phase transitions relative to nanocubes capped with nonpolar oleic acid (OA) ligands.}, journal={JOURNAL OF MATERIALS CHEMISTRY C}, author={Jiang, Bo and Zhao, Changhao and Metz, Peter C. and Jothi, Palani Raja and Kavey, Benard and Reven, Linda and Lindner-D'Addario, Michael and Jones, Jacob L. and Caruntu, Gabriel and Page, Katharine}, year={2022}, month={Apr} }
 @article{zhao_li_zhang_li_jones_2019, title={Mechanisms underpinning the ultrahigh piezoelectricity in Sm-doped 0.705Pb(Mg1/3Nb2/3)O-3-0.295PbTiO(3): Temperature-induced metastable local structure and field-induced polarization rotation}, volume={126}, ISSN={["1089-7550"]}, DOI={10.1063/1.5089477}, abstractNote={The solid solution of (100 − x)%Pb(Mg1/3Nb2/3)O3-x%PbTiO3 (PMN-xPT) exhibits ultrahigh piezoelectric and dielectric properties near the morphotropic phase boundary compositions and, thus, has been extensively studied in recent years. Recently, 2.5 mol. % Sm-doped PMN-29PT polycrystalline ceramics were reported to possess the highest piezoelectric coefficients (∼1500 pC/N) among all reported piezoceramics, but the atomic-scale mechanisms for such high piezoelectric properties are not yet clear. In this paper, in situ X-ray diffraction and X-ray total scattering measurements during the application of an electric field, together with in situ total scattering measurement at different temperatures, were conducted for 2.5 mol. % Sm-doped PMN-29.5PT (2.5Sm-PMN-29.5PT). Both the largest field-induced strain and the piezoelectric response were found in the crystallites oriented with their ⟨100⟩PC directions parallel to the applied field. The local Pb displacement was analyzed using the reverse Monte Carlo method based on the pair distribution functions at different temperatures, where a temperature-induced directional change of Pb displacement was observed. Based on the experimental observations, a field-induced polarization rotation is suggested to be the dominant mechanism for the ultrahigh piezoelectricity of the 2.5Sm-PMN-29.5PT ceramic, while the ease of polarization rotation is possibly attributed to the temperature-induced metastable local monoclinic symmetries with their polar axes close to ⟨111⟩PC.}, number={7}, journal={JOURNAL OF APPLIED PHYSICS}, author={Zhao, Changhao and Li, Fei and Zhang, Shujun and Li, Shengtao and Jones, Jacob L.}, year={2019}, month={Aug} }
 @article{yu_zhao_li_li_zhu_2018, title={A novel approach to align carbon nanotubes via water-assisted shear stretching}, volume={164}, ISSN={["1879-1050"]}, url={https://doi.org/10.1016/j.compscitech.2018.05.028}, DOI={10.1016/j.compscitech.2018.05.028}, abstractNote={Floating catalyst chemical vapor deposition (FCCVD) can produce buckypaper, a kind of CNT film, at large-scale with low cost. However, individual CNTs in the buckypaper are mostly randomly oriented, which significantly limits their electrical and mechanical properties. Here we report an innovative approach, water-assisted shear stretching (WASS), which can significantly improve CNT alignments and consequently enhance the electrical and mechanical properties. In addition, we define a unique "alignment factor" to quantify the alignment degree, and to estimate the effect of alignment on the mechanical and electrical properties of CNT assemblies. The high mechanical strength and excellent electrical conductivity of the WASS-processed buckypaper enhance their potential for applications in new electronic technologies and high-strength lightweight aerospace structures.}, journal={COMPOSITES SCIENCE AND TECHNOLOGY}, author={Yu, Yingying and Zhao, Changhao and Li, Qingwen and Li, Jianying and Zhu, Yuntian}, year={2018}, month={Aug}, pages={1–7} }
 @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{yu_zhang_yildiz_deng_zhao_bradford_li_zhu_2017, title={Investigation of microcombing parameters in enhancing the properties of carbon nanotube yarns}, volume={134}, ISSN={["1873-4197"]}, DOI={10.1016/j.matdes.2017.08.035}, abstractNote={Microcombing has been reported as a novel processing approach for reducing waviness and improving alignment of carbon nanotubes (CNTs), which effectively enhances the performance of materials made from CNT sheets. In this study, we have systematically investigated the effects of microcombing parameters on the properties of CNT yarns. It is found that the electrical and mechanical properties of CNT yarns first improved with increasing degree of microcombing and then degraded with over-combing. At the optimum degree of microcombing, the electrical conductivity, tensile strength, and Young's modulus of the CNT yarns were improved to 140%, 140%, and 230%, respectively, over those of uncombed yarns. The enhanced yarn properties were resulted from reduced nanotube waviness, improved CNT alignment and denser packing structure, which led to a more uniform yarn structure. On the other hand, over-combing degraded structural uniformity, resulting in lower electrical and mechanical properties. These observations are expected to help with future selection of microcombing parameters for producing high-quality CNT yarns and polymer-CNT composite yarns for superior electrical and mechanical properties.}, journal={MATERIALS & DESIGN}, author={Yu, Yingying and Zhang, Liwen and Yildiz, Ozkan and Deng, Haotian and Zhao, Changhao and Bradford, Philip D. and Li, Jianying and Zhu, Yuntian}, year={2017}, month={Nov}, pages={181–187} }
 @article{zhao_hou_chung_yu_liu_li_jones_2017, title={Local structural behavior of PbZr0.5Ti0.5O3 during electric field application via in situ pair distribution function study}, volume={122}, number={17}, journal={Journal of Applied Physics}, author={Zhao, C. H. and Hou, D. and Chung, C. C. and Yu, Y. Y. and Liu, W. F. and Li, S. T. and Jones, J. L.}, year={2017} }