Studying the phase transition, thermal expansion, and heat capacity of technetium mononitride by first-principles calculations

作者：Liu, Z. J.^*; Sun, X. W.; Song, T.; Ma, Q.; Guo, Y.

来源：Chemical Physics Letters, 2016, 649: 64-67.

DOI：10.1016/j.cplett.2016.02.044

• HIGH-PRESSURE
• TEMPERATURE
• THERMODYNAMICS
• CARBIDE
• PTC

The pressure-induced B3-B1 phase transition and some interesting thermodynamic properties for B3 structure of ideal stoichiometric technetium mononitride (TcN) have been studied systematically by first-principles calculations. It is found that TcN has a B3 ground-state phase at zero pressure and the transition pressure from B3 to B1 structure determined by the energy vs volume curves is about 35 GPa. Through the quasi-harmonic Debye model, the dependences of thermal expansion coefficient, constant volume heat capacity, and constant-pressure heat capacity of TcN with B3 phase on temperature up to 1600 K are successfully predicted at 0, 10, 20 and 35 GPa pressures, respectively.

• 出版日期2016-4
• 单位兰州交通大学; 兰州城市学院; 兰州理工大学