skip to main content

Title: Structure determination of the high-pressure phase of CdSe

Structural phase transition sequence of CdSe has been investigated at pressures up to 60 GPa under quasi-hydrostatic conditions using synchrotron X-ray diffraction. A phase transition from the wurtzite type (B4) to the NaCl-type (B1) structure has been observed, followed by another phase transition to an orthorhombic structure at 27 GPa, in agreement with previous reports. We show that this high-pressure orthorhombic phase has a Pnma symmetry rather than being a Cmcm-symmetric structure as previously suggested. From our observations, the appearance of the new reflections and reflection splitting with increasing pressure is due to the change of atomic relative positions in crystal lattice and the difference in the compression ratio of lattice parameters for the Pnma structure, and we find no evidence for the third phase transition reported previously. The pressure-induced phase transition of CdSe has been further confirmed by the density-functional theory calculations.
Authors:
; ; ;  [1] ;  [2] ;  [3]
  1. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, 100049 Beijing (China)
  2. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)
  3. Institute of Fluid Physics, China Academy of Engineering Physics, P. O. Box 919-102, Mianyang, Sichuan 621900 (China)
Publication Date:
OSTI Identifier:
22304169
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CADMIUM SELENIDES; COMPRESSION RATIO; COMPUTERIZED SIMULATION; CRYSTAL STRUCTURE; DENSITY FUNCTIONAL METHOD; LATTICE PARAMETERS; ORTHORHOMBIC LATTICES; PHASE TRANSFORMATIONS; PRESSURE RANGE GIGA PA; REFLECTION; SYMMETRY; SYNCHROTRONS; X-RAY DIFFRACTION