Studies on thermophysical properties of ThW2O8 and UWO6

Abstract

Thermal stability and expansion behavior of ThW 2 O 8 and UWO 6 were studied using thermogravimetry and high-temperature X-ray diffraction techniques. ThW 2-O 8 and UWO 6 showed positive thermal expansion in vacuum from ambient to 1273 and 1073 K, respectively. Heat capacity for ThW 2 O 8 (s) and UWO 6 (s) was measured in argon atmosphere using heat flux-type differential scanning calorimeter, and thermodynamic functions of these compounds have been computed from the measured heat capacity data. The structural study of UWO 6 was also carried out from powder X-ray diffraction data using Rietveld profile method.

Synthesis and thermal, optical and magnetic properties of new Mn2+-doped and Eu3+-co-doped scheelites

“…-doped and Eu 3? -co-doped calcium molybdato-tungstates with the following formula of Ca 1−3x−y Mn y ⌷ x Eu 2x (MoO 4 ) 1−3x (WO 4 ) 3x were obtained by the two-step synthesis, in which both the steps consist of high-temperature sintering which is very often used in a preparation of many molybdates and tungstates [27][28][29][30][31][32]. The following reactants were used in the first step of synthesis: CaCO 3 , MnO, MoO 3 , Eu 2 O 3 and WO 3 (all raw materials of high-purity grade min.…”