High-temperature heat capacity and thermal expansion of FeTa$_{2}$O$_{6}$

The heat capacity of the synthesized FeTa$_{2}$O$_{6}$ iron tantalate was measured in the temperature range of 323–1103 K by the ratio method using a thermal analyzer with combined thermogravimetry and scanning calorimetry. The phase transition temperatures were determined. Structural changes and thermal expansion of the oxide in the range of 300–1173 K were studied by high-temperature X-ray diffraction. The temperature dependences of the unit cell parameters were approximated by third-degree polynomials. From the data obtained, the values of thermal expansion coefficients and anisotropy factors were calculated.