中国物理B ›› 2016, Vol. 25 ›› Issue (1): 16701-016701.doi: 10.1088/1674-1056/25/1/016701
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
Shi-Quan Feng(冯世全), Hua-Ping Zang(臧华平), Yong-Qiang Wang(王永强), Xin-Lu Cheng(程新路), Jin-Sheng Yue(岳金胜)
Shi-Quan Feng(冯世全)1, Hua-Ping Zang(臧华平)2, Yong-Qiang Wang(王永强)1, Xin-Lu Cheng(程新路)3, Jin-Sheng Yue(岳金胜)4
摘要: Using the linear-response method, we investigate the phonon properties of β -cristobalite crystal under electronic excitation effect. We find that the transverse-acoustic phonon frequency becomes imaginary as the electron temperature is increased, which means that the lattice of β -cristobalite becomes unstable under intense laser irradiation. In addition, for the optic phonon mode, the LO(H)-TO(H) splitting disappears when the electronic temperature reaches a certain value, corresponding to the whole transverse-acoustic phonon branches becoming negative. It means that the electronic excitation destroys the macroscopic electric field of β -cristobalite. Based on the calculated phonon band structures, some thermodynamic properties are calculated as a function of temperature at different electronic temperatures. These investigations provide evidence that non-thermal melting takes place during a femtosecond pulse laser interaction with β -cristobalite.
中图分类号: (Thermodynamic properties)