@article{Baker2016, abstract = {A new sample cell assembly design for the Paris-Edinburgh type large-volume press for simultaneous measurements of X-ray diffraction, electrical resistance, Seebeck coefficient and relative changes in the thermal conductance at high pressures has been developed. The feasibility of performingin situmeasurements of the Seebeck coefficient and thermal measurements is demonstrated by observing well known solid–solid phase transitions of bismuth (Bi) up to 3 GPa and 450 K. A reversible polarity flip has been observed in the Seebeck coefficient across the Bi-I to Bi-II phase boundary. Also, successful Seebeck coefficient measurements have been performed for the classical high-temperature thermoelectric material PbTe under high pressure and temperature conditions. In addition, the relative change in the thermal conductivity was measured and a relative change in ZT, the dimensionless figure of merit, is described. This new capability enables pressure-induced structural changes to be directly correlated to electrical and thermal properties.}, author = {Baker, Jason and Kumar, Ravhi and Park, Changyong and Kenney-Benson, Curtis and Cornelius, Andrew and Velisavljevic, Nenad}, doi = {10.1107/s1600577516014521}, journal = {Journal of Synchrotron Radiation}, month = {oct}, pages = {1368-1378}, title = {High-pressure Seebeck coefficients and thermoelectric behaviors of Bi and PbTe measured using a Paris-Edinburgh cell}, url = {https://oadoi.org/10.1107/s1600577516014521}, volume = {23}, year = {2016} } @article{Barabash2015, author = {Barabash, Rozaliya I. and Barabash, Oleg M. and Popov, Dmitry and Shen, Guoyin and Park, Changyong and Yang, Wenge}, doi = {10.1016/j.actamat.2015.01.010}, journal = {Acta Materialia}, month = {apr}, pages = {344-349}, title = {Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu}, url = {https://doi.org/10.1016/j.actamat.2015.01.010}, volume = {87}, year = {2015} } @article{Chu2016, author = {Chu, Shengqi and Park, Changyong and Shen, Guoyin}, doi = {10.1103/physrevb.94.020101}, journal = {Physical review B}, month = {jul}, title = {Structural characteristic correlated to the electronic band gap inMoS2}, url = {https://link.aps.org/accepted/10.1103/PhysRevB.94.020101}, volume = {94}, year = {2016} } @article{Hou2016, abstract = {AbstractThe interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5 Å resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.}, author = {Hou, Binyang and Kim, Seunghyun and Kim, Taeho and Kim, Jongjin and Hong, Seungbum and Bahn, Chi Bum and Park, Changyong and Kim, Ji Hyun}, doi = {10.1038/srep27916}, journal = {Scientific Reports}, month = {jun}, title = {The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Ångström Resolution}, url = {http://dx.doi.org/10.1038/srep27916}, volume = {6}, year = {2016} } @article{Kono2015, author = {Kono, Yoshio and Kenney-Benson, Curtis and Shibazaki, Yuki and Park, Changyong and Wang, Yanbin and Shen, Guoyin}, doi = {10.1063/1.4927227}, journal = {Review of Scientific Instruments}, month = {jul}, pages = {072207}, title = {X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press}, url = {https://aip.scitation.org/doi/10.1063/1.4927227}, volume = {86}, year = {2015} } @article{Li2017, author = {Li, Quanjun and Zhang, Huafang and Lin, Chuanlong and Tian, Fubo and Smith, Jesse S. and Park, Changyong and Liu, Bingbing and Shen, Guoyin}, doi = {10.1016/j.jallcom.2017.03.164}, journal = {Journal of Alloys and Compounds}, month = {jun}, pages = {260-266}, title = {Pressure-induced phase transitions and insulator-metal transitions in VO2 nanoparticles}, url = {https://oadoi.org/10.1016/j.jallcom.2017.03.164}, volume = {709}, year = {2017} } @article{Li2019, author = {Li, Rui and Liu, Jing and Popov, Dmitry and Park, Changyong and Meng, Yue and Shen, Guoyin}, doi = {10.1103/physrevb.100.224106}, journal = {Physical review B}, month = {dec}, title = {Experimental observations of large changes in electron density distributions in β−Ge}, url = {https://oadoi.org/10.1103/physrevb.100.224106}, volume = {100}, year = {2019} } @article{Lin2016, author = {Lin, Chuanlong and Smith, Jesse S. and Sinogeikin, Stanislav V. and Park, Changyong and Kono, Yoshio and Kenney-Benson, Curtis and Rod, Eric and Shen, Guoyin}, doi = {10.1063/1.4940771}, journal = {Journal of Applied Physics}, month = {jan}, pages = {045902}, title = {Kinetics of the B1-B2 phase transition in KCl under rapid compression}, url = {https://aip.scitation.org/doi/10.1063/1.4940771}, volume = {119}, year = {2016} } @article{Palomares2015, abstract = {Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron X-ray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature and apparatus stability at high temperatures. Isochronal annealing between 300 and 1100 K revealed two-stage and one-stage defect recovery processes for irradiated CeO2 and ThO2, respectively, indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high-temperature defect recovery mechanisms of CeO2 and ThO2.}, author = {Palomares, Raul I. and Tracy, Cameron L. and Zhang, Fuxiang and Park, Changyong and Popov, Dmitry and Trautmann, Christina and Ewing, Rodney C. and Lang, Maik}, doi = {10.1107/s160057671500477x}, journal = {Journal of Applied Crystallography}, month = {apr}, pages = {711-717}, title = {In situdefect annealing of swift heavy ion irradiated CeO2and ThO2using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell}, url = {https://www.researchgate.net/profile/Changyong_Park/publication/275259987_In_situ_defect_annealing_of_swift_heavy_ion_irradiated_CeO_2_and_ThO_2_using_synchrotron_X-ray_diffraction_and_a_hydrothermal_diamond_anvil_cell/links/55a90b7008ae481aa7f92e6f.pdf}, volume = {48}, year = {2015} } @article{Park2018, author = {Park, Sulgiye and Tracy, Cameron L. and Zhang, Fuxiang and Park, Changyong and Trautmann, Christina and Tkachev, Sergey N. and Lang, Maik and Mao, Wendy L. and Ewing, Rodney C.}, doi = {10.1039/c7cp08664d}, journal = {Physical Chemistry Chemical Physics}, month = {jan}, pages = {6187-6197}, title = {Radiation-induced disorder in compressed lanthanide zirconates}, url = {https://oadoi.org/10.1039/c7cp08664d}, volume = {20}, year = {2018} } @article{Rainwater2016, author = {Rainwater, Ben H. and Velisavljevic, Nenad and Park, Changyong and Sun, Haibin and Waller, Gordon H. and Tsoi, Georgiy M. and Vohra, Yogesh K. and Liu, Meilin}, doi = {10.1016/j.ssi.2016.05.010}, journal = {Solid State Ionics}, month = {sep}, pages = {59-65}, title = {High pressure structural study of samarium doped CeO2 oxygen vacancy conductor — Insight into the dopant concentration relationship to the strain effect in thin film ionic conductors}, url = {https://doi.org/10.1016/j.ssi.2016.05.010}, volume = {292}, year = {2016} } @article{Sereika2020, abstract = {AbstractThe perovskite NaOsO3 has a metal–insulator transition at temperature 410 K, which is delicate, intriguing, and provokes a lot of debate on its nature. Our combined electrical resistance, Raman, and synchrotron x-ray diffraction experiments show that the insulating ground state in this osmate endures under high pressure up to at least 35 GPa. In this pressure range, compression reveals hidden hysteretic resistance properties with a transient metallic state near 200 K, manifested three electronic character anomalies (at 1.7, 9.0, and 25.5 GPa), and a structural transition to the singular polar phase (at ~18 GPa). We distinguish NaOsO3 from the regular crystallographic behavior of perovskites, though the electrical specificities resemble iridates and nickelates. The theoretical first-principle band structure and lattice dynamics calculations demonstrate that the magnetically itinerant Lifshitz-type mechanism with spin–orbit and spin–phonon interactions is responsible for these pressure-induced changes. Our findings provide another new playground for the emergence of new states in 5d materials by using high-pressure methods.}, author = {Sereika, Raimundas and Liu, Peitao and Kim, Bongjae and Kim, Sooran and Zhang, Jianbo and Chen, Bijuan and Yamaura, Kazunari and Park, Changyong and Franchini, Cesare and Ding, Yang and Mao, Ho-Kwang}, doi = {10.1038/s41535-020-00269-3}, journal = {npj Quantum Materials}, month = {sep}, title = {Aberrant electronic and structural alterations in pressure tuned perovskite NaOsO3}, url = {https://www.nature.com/articles/s41535-020-00269-3.pdf}, volume = {5}, year = {2020} } @article{Stagno2015, abstract = {Icosahedrite, the first natural quasicrystal with composition Al63Cu24Fe13, was discovered in several grains of the Khatyrka meteorite, a CV3 carbonaceous chondrite. The presence of icosahedrite associated with high-pressure phases like ahrensite and stishovite indicates formation at high pressures and temperatures due to an impact-induced shock. Previous experimental studies on the stability of synthetic icosahedral AlCuFe have either been limited to ambient pressure, for which they indicate incongruent melting at ∼1123 K, or limited to room-temperature, for which they indicate structural stability up to about 35 GPa. These data are insufficient to experimentally constrain the formation and stability of icosahedrite under the conditions of high pressure and temperature that formed the Khatyrka meteorite. Here we present the results of room-temperature, high-pressure diamond-anvil cells measurements of the compressional behavior of synthetic icosahedrite up to ∼50 GPa. High P-T experiments were also carried out using both laser-heated diamond-anvil cells combined with in situ synchrotron X-ray diffraction (at ∼42 GPa) and multi-anvil apparatus (at 21 GPa) to investigate the structural evolution and crystallization of possible coexisting phases. The results demonstrate that the quasiperiodic order of icosahedrite is retained over the P-T range explored. We find that pressure acts to stabilize the icosahedral symmetry at temperatures much higher than previously reported. Direct solidification of AlCuFe quasicrystals from an unusual Al-Cu-rich melt is possible but it is limited to a narrow temperature range. Alternatively, quasicrystals may form after crystallization through solidsolid reactions of Al-rich phases. In either case, our results show that quasicrystals can preserve their structure even after hypervelocity impacts spanning a broad range of pressures and temperatures.}, author = {Stagno, Vincenzo and Bindi, Luca and Park, Changyong and Tkachev, Sergey and Prakapenka, Vitali B. and Mao, H.-K. and Hemley, Russell J. and Steinhardt, Paul J. and Fei, Yingwei}, doi = {10.2138/am-2015-5412}, journal = {American Mineralogist}, month = {nov}, pages = {2412-2418}, title = {Quasicrystals at extreme conditions: The role of pressure in stabilizing icosahedral Al63Cu24Fe13at high temperature}, url = {https://www.researchgate.net/profile/Vincenzo_Stagno/publication/281036628_Quasicrystals_at_extreme_conditions_The_role_of_pressure_in_stabilizing_icosahedral_Al63Cu24Fe13_at_high_temperature/links/55d27a1e08ae7fb244f53f4c.pdf}, volume = {100}, year = {2015} } @article{Wang2016, abstract = {The structure stability under high pressure and thermal expansion behavior of Na3OBr and Na4OI2, two prototypes of alkali-metal-rich antiperovskites, were investigated by in situ synchrotron X-ray diffraction techniques under high pressure and low temperature. Both are soft materials with bulk modulus of 58.6 GPa and 52.0 GPa for Na3OBr and Na4OI2, respectively. The cubic Na3OBr structure and tetragonal Na4OI2 with intergrowth K2NiF4structure are stable under high pressure up to 23 GPa. Although being a characteristic layered structure,Na4OI2 exhibits nearly isotropic compressibility. Negative thermal expansion was observed at low temperature range (20–80 K) in both transition-metal-free antiperovskites for the first time. The robust high pressurestructure stability was examined and confirmed by first-principles calculations among various possible polymorphisms qualitatively. The results provide in-depth understanding of the negative thermal expansion and robust crystal structure stability of these antiperovskite systems and their potential applications.}, author = {Wang, Yonggang and Wen, Ting and Park, Changyong and Kenney-Benson, Curtis and Pravica, Michael and Yang, Wenge and Zhao, Yusheng}, doi = {10.1063/1.4940020}, journal = {Journal of Applied Physics}, month = {jan}, pages = {025901}, title = {Robust high pressure stability and negative thermal expansion in sodium-rich antiperovskites Na3OBr and Na4OI2}, url = {https://oadoi.org/10.1063/1.4940020}, volume = {119}, year = {2016} } @article{Wang2016_2, author = {Wang, Y. Q. and Lu, P. C. and Wu, J. J. and Liu, J. and Wang, X. C. and Zhao, J. Y. and Bi, W. and Alp, E. E. and Park, C. Y. and Popov, D. and Jin, C. Q. and Sun, J. and Lin, J. F.}, doi = {10.1103/physrevb.94.014516}, journal = {Physical review B}, month = {jul}, title = {Phonon density of states of single-crystalSrFe2As2across the collapsed phase transition at high pressure}, url = {https://link.aps.org/accepted/10.1103/PhysRevB.94.014516}, volume = {94}, year = {2016} } @article{Yan2016, abstract = {AbstractUnder high pressure, the phase transition mechanism and mechanical property of material are supposed to be largely associated with the transformation induced elastic strain. However, the experimental evidences for such strain are scanty. The elastic and plastic properties of ZnO, a leading material for applications in chemical sensor, catalyst, and optical thin coatings, were determined using in situ high pressure synchrotron axial and radial x-ray diffraction. The abnormal elastic behaviors of selected lattice planes of ZnO during phase transition revealed the existence of internal elastic strain, which arise from the lattice misfit between wurtzite and rocksalt phase. Furthermore, the strength decrease of ZnO during phase transition under non-hydrostatic pressure was observed and could be attributed to such internal elastic strain, unveiling the relationship between pressure induced internal strain and mechanical property of material. These findings are of fundamental importance to understanding the mechanism of phase transition and the properties of materials under pressure.}, author = {Yan, Xiaozhi and Dong, Haini and Li, Yanchun and Lin, Chuanlong and Park, Changyong and He, Duanwei and Yang, Wenge}, doi = {10.1038/srep24958}, journal = {Scientific Reports}, month = {may}, title = {Phase transition induced strain in ZnO under high pressure}, url = {http://dx.doi.org/10.1038/srep24958}, volume = {6}, year = {2016} } @article{Zeng2016, abstract = {Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its "disordered" structure. Recently we found that under compression, the volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q1). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co2 MG. This transition is, in effect, the equivalent of a continuous "composition" change of 4f-localized "big Ce" to 4f-itinerant "small Ce," indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs.}, author = {Zeng, Qiaoshi and Lin, Yu and Liu, Yijin and Zeng, Zhidan and Shi, Crystal Y. and Zhang, Bo and Lou, Hongbo and Sinogeikin, Stanislav V. and Kono, Yoshio and Kenney-Benson, Curtis and Park, Changyong and Yang, Wenge and Wang, Weihua and Sheng, Hongwei and Mao, Ho-Kwang and Mao, Wendy L.}, doi = {10.1073/pnas.1525390113}, journal = {Proceedings of the National Academy of Sciences}, month = {feb}, pages = {1714-1718}, title = {General 2.5 power law of metallic glasses}, url = {http://www.pnas.org/content/113/7/1714.full.pdf}, volume = {113}, year = {2016} } @article{Zhang2016, author = {Zhang, F. X. and Tracy, C. L. and Shamblin, J. and Palomares, R. I. and Lang, M. and Park, S. and Park, C. and Tkachev, S. and Ewing, R. C.}, doi = {10.1039/c6ra11185h}, journal = {RSC Advances}, month = {jan}, pages = {94287-94293}, title = {Pressure-induced phase transitions of β-type pyrochlore CsTaWO6}, url = {https://doi.org/10.1039/c6ra11185h}, volume = {6}, year = {2016} } @article{Zhang2017, author = {Zhang, F. X. and Jin, K. and Zhao, Shijun and Mu, S. and Bei, Hongbin and Liu, J. C. and Xue, H. Z. and Popov, D. and Park, Changyong and Stocks, G. M. and Weber, William J. and Zhang, Yanwen}, doi = {10.1063/1.4982705}, journal = {Journal of Applied Physics}, month = {apr}, pages = {165105}, title = {X-ray absorption investigation of local structural disorder in Ni1-xFex (x = 0.10, 0.20, 0.35, and 0.50) alloys}, url = {https://aip.scitation.org/doi/10.1063/1.4982705}, volume = {121}, year = {2017} } @article{Zhou2016, author = {Zhou, Yonghui and Chen, Xuliang and Zhang, Ranran and Shao, Jifeng and Wang, Xuefei and An, Chao and Zhou, Ying and Park, Changyong and Tong, Wei and Pi, Li and Yang, Zhaorong and Zhang, Changjin and Zhang, Yuheng}, doi = {10.1103/physrevb.93.144514}, journal = {Physical review B}, month = {apr}, title = {Pressure-induced reemergence of superconductivity in topological insulatorSr0.065Bi2Se3}, url = {https://link.aps.org/accepted/10.1103/PhysRevB.93.144514}, volume = {93}, year = {2016} }