Structural Characteristics and Thermodynamic Functions of Compounds Ba(La_1–xPr_x)₂WO₇ (x from 0.005 to 0.05)

Abstract

A sol–gel method was used to synthesize barium, lanthanum, and tungsten-based samples doped with praseodymium Ba­(La1–x Pr x )2WO7, where x = 0.005 ÷ 0.05. The morphological and elemental analyses of the samples were carried out by electron probe microanalysis. A full-profile refinement of the crystal structure of the compounds belonging to the monoclinic system with the space group P1121/b was carried out. Using the adiabatic calorimetry method, the heat capacity of the samples was measured and the thermodynamic functions in the range of 5–320 K were found. In the heat capacity of the samples below 15 K, anomalies were detected and the excessive and lattice heat capacities were determined.