Thermodynamic stability of new phase Bi12.5Sm1.5ReO24.5

TL;DR

This study reports the first synthesis and thermodynamic stability analysis of a new cubic phase Bi12.5Sm1.5ReO24.5, demonstrating its stability relative to binary oxides at room temperature.

Contribution

The paper introduces a novel phase Bi12.5Sm1.5ReO24.5, synthesized via solid-state reaction, and provides its thermodynamic stability data through calorimetry.

Findings

Bi12.5Sm1.5ReO24.5 is a cubic structure (space group Fm3m).

The phase is thermodynamically stable at room temperature.

Standard molar enthalpy of formation was determined.

Abstract

The Bi12.5Sm1.5ReO24.5 phase has been synthesized for the first time. The preparation of Bi12.5Sm1.5ReO24.5 has been performed by solid-state reaction from Bi2O3, Gd2O3, Re2O7. The X-ray measurements have showed that Bi12.5Sm1.5ReO24.5 was cubic structure (space group Fm3m). The standard molar enthalpy of formation of Bi12.5Sm1.5ReO24.5 has been determined by solution calorimetry combining the enthalpies of dissolution of Bi12.5Sm1.5ReO24.5 and 6.25Bi2O3 + 0.75Sm2O3 + 0.5Re2O7 mixture in 2 M HCl and literature data. It has been obtained that above-mentioned phase is thermodynamically stable with respect to their decomposition into binary oxides at room temperatures.