Thermophysical measurements on dysprosium and gadolinium titanates

Abstract

Dysprosium and gadolinium titanates were prepared by the solid state route and by the wet chemical route. The compounds were characterized using inductively coupled plasma mass spectrometry (ICPMS) and X-ray diffraction (XRD) techniques. Their thermal expansion coefficients were measured using high temperature X-ray diffraction technique. The quasi-isotropic mean linear thermal expansion coefficient α ̄ m of Dy 2TiO 5 and Gd 2TiO 5 at room temperature are 6.55 × 10 −6 and 6.56 × 10 −6 K −1, respectively, and in the temperature range 298–1573 K are 1.006 × 10 −5 and 1.023 × 10 −5 K −1, respectively. Heat capacity measurements were carried out in the temperature range 320–820 K using differential scanning calorimetry. From the polynomial fit the C p,298 of Dy 2TiO 5 and Gd 2TiO 5 have been computed to be 178.26 and 168.61 J K −1 mol −1, respectively.