skip to main content

SciTech ConnectSciTech Connect

Title: High-pressure structural and elastic properties of Tl₂O₃

The structural properties of Thallium (III) oxide (Tl₂O₃) have been studied both experimentally and theoretically under compression at room temperature. X-ray powder diffraction measurements up to 37.7 GPa have been complemented with ab initio total-energy calculations. The equation of state of Tl₂O₃ has been determined and compared to related compounds. It has been found experimentally that Tl₂O₃ remains in its initial cubic bixbyite-type structure up to 22.0 GPa. At this pressure, the onset of amorphization is observed, being the sample fully amorphous at 25.2 GPa. The sample retains the amorphous state after pressure release. To understand the pressure-induced amorphization process, we have studied theoretically the possible high-pressure phases of Tl₂O₃. Although a phase transition is theoretically predicted at 5.8 GPa to the orthorhombic Rh₂O₂-II-type structure and at 24.2 GPa to the orthorhombic α-Gd₂S₃-type structure, neither of these phases were observed experimentally, probably due to the hindrance of the pressure-driven phase transitions at room temperature. The theoretical study of the elastic behavior of the cubic bixbyite-type structure at high-pressure shows that amorphization above 22 GPa at room temperature might be caused by the mechanical instability of the cubic bixbyite-type structure which is theoretically predicted above 23.5 GPa.
Authors:
;  [1] ;  [2] ;  [3] ;  [2] ;  [4] ; ; ;  [5] ;
  1. Centro de Tecnologías Físicas, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain)
  2. Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, 46100 Burjassot (Spain)
  3. (United Kingdom)
  4. (Germany)
  5. Instituto de Diseño para la Fabricación y Producción Automatizada, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain)
Publication Date:
OSTI Identifier:
22305750
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; CRYSTAL STRUCTURE; ELASTICITY; EQUATIONS OF STATE; GADOLINIUM SULFIDES; INSTABILITY; ORTHORHOMBIC LATTICES; PHASE TRANSFORMATIONS; PRESSURE RANGE GIGA PA; PRESSURE RELEASE; RHODIUM OXIDES; TEMPERATURE RANGE 0273-0400 K; THALLIUM OXIDES; X-RAY DIFFRACTION