Correlated High-Pressure Phase Sequence of VO₂ under Strong Compression

Journal Article · 18 April 2018 · Journal of Physical Chemistry Letters

DOI: https://doi.org/10.1021/acs.jpclett.8b00771 · OSTI ID:1468622

Xie, Sheng-Yi  ^[1]; Wang, Luhong ^[2]; Liu, Fuyang ^[3]; Li, Xian-Bin ^[4]; Bai, Ligang ^[5]; Prakapenka, Vitali B. ^[6]; Cai, Zhonghou ^[7]; Mao, Ho-kwang ^[8]; Zhang, Shengbai ^[9]; Liu, Haozhe ^[10]

---

1. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Changchun and Beijing (China); Hunan Univ., Changsha (China). School of Physics and Electronics
2. Harbin Inst. of Technology (China)
3. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Changchun and Beijing (China)
4. Jilin Univ., Changchun (China). State Key Lab. on Integrated Optoelectronics and College of Electronic Science and Engineering
5. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)
6. Univ. of Chicago, IL (United States). Center for Advanced Radiation Sources
7. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
8. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Changchun and Beijing (China); Carnegie Inst. of Washington, Washington, DC (United States). Geophysical Lab.
9. Jilin Univ., Changchun (China). State Key Lab. on Integrated Optoelectronics and College of Electronic Science and Engineering; Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Physics, Applied Physics and Astronomy; Beijing Computational Science Research Center (CSRC), Beijing (China)
10. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Changchun and Beijing (China); Harbin Inst. of Technology (China)

Understanding how the structures of a crystal behave under compression is a fundamental issue both for condensed matter physics and for geoscience. Traditional description of a crystal as the stacking of a unit cell with special symmetry has gained much success on the analysis of physical properties. Unfortunately, it is hard to reveal the relationship between the compressed phases. Taking the family of metal dioxides (MO₂) as an example, the structural evolution, subject to fixed chemical formula and highly confined space, often appears as a set of random and uncorrelated events. In this work, we provide an alternative way to treat the crystal as the stacking of the coordination polyhedron and then discover a unified structure transition pattern, in our case VO₂. X-ray diffraction (XRD) experiments and first-principles calculations show that the coordination increase happens only at one apex of the V-centered octahedron in an orderly fashion, leaving the base plane and the other apex topologically intact. The polyhedron evolves toward increasing their sharing, indicating a general rule for the chemical bonds of MO₂ to give away the ionicity in exchange for covalency under pressure.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); National Natural Science Foundation of China (NSFC)
• Grant/Contract Number: AC02-06CH11357; U153042; 11374075; 11374119; 11704111; 91423102; 91323301; JC201005; HIT. BRET1.2010002; HIT. IBRSEM.A.201403; HNU. 531107050916; SC0002623; EAR-1128799; FG02-94ER14466; EAR 11-57758
• OSTI ID: 1468622
• Journal Information: Journal of Physical Chemistry Letters, Vol. 9, Issue 9; ISSN 1948-7185
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English