Revisit of Pressure-Induced Phase Transition in PbSe: Crystal Structure, and Thermoelastic and Electrical Properties.
Lead selenide, PbSe, an important lead chalcogenide semiconductor, has been investigated using in-situ high-pressure/high-temperature synchrotron X-ray diffraction and electrical resistivity measurements. For the first time, high-quality X-ray diffraction data were collected for the intermediate orthorhombic PbSe. Combined with ab initio calculations, we find a Cmcm, InI-type symmetry for the intermediate phase, which is structurally more favorable than the anti-GeS-type Pnma. At room temperature, the onset of the cubic-orthorhombic transition was observed at ∼3.5 GPa with a ∼3.4% volume reduction. At an elevated temperature of 1000 K, the reversed orthorhombic-to-cubic transition was observed at 6.12 GPa, indicating a positive Clapeyron slope for the phase boundary. Interestingly, phase-transition induced elastic softening in PbSe was also observed, which can be mainly attributed to the loosely bonded trigonal prisms along the b-axis in the Cmcm structure. In a comparison with the cubic phase, orthorhombic PbSe exhibits a large negative pressure dependence of electrical resistivity. In addition, thermoelastic properties of orthorhombic PbSe have been derived from isothermal compression data, such as the temperature derivative of bulk modulus and thermally induced pressure.
§Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Shanmin
S
Wang
∥Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China.
Chengpeng
C
Zang
Yongkun
Y
Wang
Liping
L
Wang
§Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Jianzhong
J
Zhang
Christian
C
Childs
⊥Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China.
Hui
H
Ge
§Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Hongwu
H
Xu
#Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794, United States.
Haiyan
H
Chen
Duanwei
D
He
§Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Yusheng
Y
Zhao