High-pressure structural and elastic properties of Tl2O3

Abstract

High pressure transport, structural, and first principles investigations on the fluorite structured intermetallic, PtAl2 J. Appl. Phys. 111, 013507 (2012) The structural properties of Thallium (III) oxide (Tl 2 O 3 ) 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 Tl 2 O 3 has been determined and compared to related compounds. It has been found experimentally that Tl 2 O 3 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 Tl 2 O 3 . Although a phase transition is theoretically predicted at 5.8 GPa to the orthorhombic Rh 2 O 3 -II-type structure and at 24.2 GPa to the orthorhombic a-Gd 2 S 3 -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. V C 2014 AIP Publishing LLC. [http://dx

Structural and Lattice-Dynamical Properties of Tb2O3 under Compression: A Comparative Study with Rare Earth and Related Sesquioxides

“… 15 In fact, since the cubic phase can be synthesized in a number of them, from Lu to Sm as well as in Mn 2 O 3 , In 2 O 3 , and Tl 2 O 3 , its behavior under compression has been widely studied, as for instance in Lu 2 O 3 , 16 , 17 Yb 2 O 3 , 18 , 19 Tm 2 O 3 , 20 , 21 Er 2 O 3 , 22 − 24 Ho 2 O 3 , 25 − 28 Dy 2 O 3 , 29 , 30 Gd 2 O 3 , 31 − 38 Eu 2 O 3 39 − 45 Sm 2 O 3 , 34 , 46 , 47 Sc 2 O 3 , 48 − 50 Y 2 O 3 , 34 , 51 − 61 Mn 2 O 3 , 62 − 65 In 2 O 3 , 66 − 70 and Tl 2 O 3 . 71 Moreover, the equation of state of several RE SOs of C-, B-, and A-type has been studied comparatively. 72 …”

Correlated structural and electronic phase transformations in transition metal chalcogenide under high pressure

“…Despite the broad interest on Cr 2 S 3 , few previous experimental and theoretical results can be referred on the structural and electrical transportation information under high pressure. Most structure studies under high pressure have been devoted to A 2 X 3 -type transition metal sesquioxides compared to chalcogenides, [11][12][13][14][15][16][17][18] due to their vital application in the process of ceramics as additives, grain growth inhibitors, and phase stabilizers. 19 Cr 2 O 3 , which is isoelectronic with Cr 2 S 3 , was found absent of structural phase transition to 10 GPa (Refs.…”

β−Bi2O3under compression: Optical and elastic properties and electron density topology analysis

“…Hill has shown that the Voigt and Reuss averages are limits and suggested that the actual effective B and G elastic moduli can be approximated by the arithmetic mean of the two bounds [59]. Young's (E) modulus and Poisson's ratio (ν) are calculated with the expressions [61,62]:…”