Magnesium Indate: Synthesis and Thermodynamic Properties

A method was proposed for preparing magnesium indate, and its thermodynamic properties were studied experimentally. MgIn2O4 powder was prepared by high-temperature annealing of a mixture of nanocrystalline indium oxide and magnesium oxide. The mixture was prepared by the thermal decomposition of a gel-like precursor comprising glycine and magnesium and indium nitrates. The microstructure, phase and chemical compositions of the powder produced by high-temperature annealing were studied by scanning electron microscopy, X-ray powder diffraction (XRD), and X-ray fluorescence spectrometry (XFS). The temperature-dependent heat capacity of MgIn2O4 was measured by relaxation calorimetry (RC), adiabatic calorimetry (AC), and differential scanning calorimetry (DSC) at temperatures from 4.2 to 1346 K. The experimental heat capacity curve in the range of temperatures studied shows no anomalies. The measured heat capacities were used to calculate temperature-dependent standard thermodynamic functions of MgIn2O4 in the range from 0 to 1346 K.