中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 3 March 2024 |
（1. International Joint Laboratory for Light Alloys (Ministry of Education), Shenyang National Laboratory for Materials Science, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. College of Aerospace Engineering, Chongqing University, Chongqing 400044, China;
3. Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213, China;
4. State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing 400044, China）
Abstract:The lattice dynamics and finite-temperature thermodynamic and mechanical properties of three Zr3O polymorphs, including rhombohedral (R3-c), rhombohedral (R32), and hexagonal (P6322) phases, were theoretically investigated using the first-principles calculations. The calculated lattice parameters agree well with experimental values. It is confirmed that the three Zr3O phases exhibit both dynamic and thermodynamic stability. The entropy, enthalpy, Gibbs free energy, specific heat capacity, thermal expansion coefficient, and elastic modulus as a function of temperature from 0 to 1500 K were systematically evaluated. It is found that Zr3O (R3-c) is the ground state at 0 K followed by Zr3O (R32) and Zr3O (P6322). Structural phase transitions occur from Zr3O (R3-c) to Zr3O (R32) at 50 K and then to Zr3O (P6322) at 540 K. Zr3O (R32) displays superior mechanical properties compared to the other two Zr3O phases.
Key words: first-principles; Zr3O; lattice dynamics; thermodynamic properties; elastic modulus
