The phase structure, thermodynamic properties, and dissolution behavior of Ca₅Mg₄V₆O₂₄

Abstract

A Ca5Mg4V6O24 compound was synthesized through solid‐state roasting routes under an air atmosphere, and its crystal structure and thermodynamic properties were determined using various methods. The cell parameters of Ca5Mg4V6O24 indicate that it crystallizes in cubic space group Ia3d with the unit cell parameters a = 12.442 ± 0.001 Å. X‐ray photoelectron spectroscopy also confirmed that the vanadium element in the Ca5Mg4V6O24 sample is present in the +5 state. The melting of Ca5Mg4V6O24 was detected at 1442 K. The molar heat capacity (374 J mol K−1) and entropy (688.2 J mol K−1) of Ca5Mg4V6O24 at 298.15 K were determined using physical properties measurement system, and simultaneous thermal analyzer for the first time. The solubility of Ca5Mg4V6O24 in water at different temperatures was measured and its dissolution behavior in sulfuric acid and kinetics was experimentally established.

High‐temperature phase transformation and thermodynamic properties of Ca3(VO4)2

“…For the Rietveld refinement, the pseudo‐Voigt and the spherical harmonics functions were applied to describe the Bragg reflection profile and measure the preferred orientation, respectively. More information and parameters about the Rietveld refinement are described elsewhere 18,19 . An inductively coupled plasma optical emission spectroscopy (ICP–OES) analysis, using an Optima 8000 Instrument (PerkinElmer), was carried out to quantitatively determine the vanadium content of the as‐prepared sample.…”

“…More information and parameters about the Rietveld refinement are described elsewhere. 18,19 An inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis, using an Optima 8000 Instrument (PerkinElmer), was carried out to quantitatively determine the vanadium content of the as-prepared sample.…”

The phase structure, transitions, and non-isothermal crystallization kinetics of Zn2V2O7 glass

“…In comparison, the crystallization mechanism of Zn2V2O7 was less reported in previous studies. Differential scanning calorimetry (DSC), which depends on the relationship between heat flow and temperature was intensively applied in the crystallization process to understand the reaction mechanism [12][13][14][15].…”