Phase relations, thermal conductivity and elastic properties of ZrO2 and HfO2 polymorphs at high pressures and temperatures

Dinara N Sagatova; Nursultan E Sagatov; Pavel N Gavryushkin; Sergey F Solodovnikov

doi:10.1039/d3cp04690g

Phase relations, thermal conductivity and elastic properties of ZrO₂ and HfO₂ polymorphs at high pressures and temperatures

Phys Chem Chem Phys. 2023 Dec 13;25(48):33013-33022. doi: 10.1039/d3cp04690g.

Authors

Dinara N Sagatova^{1

2}, Nursultan E Sagatov^{2

3}, Pavel N Gavryushkin^{2

3}, Sergey F Solodovnikov¹

Affiliations

¹ Nikolaev Institute of Inorganic Chemistry, Novosibirsk, Russian Federation. sagatovadn@igm.nsc.ru.
² Sobolev Institute of Geology and Mineralogy, Novosibirsk, Russian Federation.
³ Novosibirsk State University, Novosibirsk, Russian Federation.

PMID: 38032101
DOI: 10.1039/d3cp04690g

Abstract

In the present study, P-T phase diagrams of ZrO₂ and HfO₂ for a wide pressure range of 0-150 GPa at 0-2500 K were calculated for the first time using density functional theory with the method of lattice dynamics within the quasi-harmonic approximation. We calculated P-T conditions for a full sequence of high-pressure transformations, P2₁/c → Pbca → Pnma → P6̄2m, for both compounds. At low temperatures, these transformations for ZrO₂ are obtained at 7.6 GPa (P2₁/c → Pbca), 13.4 GPa (Pbca → Pnma), and 143 GPa (Pnma → P6̄2m), while for HfO₂ similar polymorphic transitions are obtained at 9 GPa (P2₁/c → Pbca), 16 GPa (Pbca → Pnma), and 126 GPa (Pnma → P6̄2m), correspondingly. At high temperatures, for both ZrO₂ and HfO₂ the P2₁/c and Pbca structures transform into the P4₂/nmc modification. In addition, the thermal conductivity and elastic properties of the ZrO₂ and HfO₂ polymorphs were calculated and compared with the available experimental and theoretical data.