Studies on structural, electrical, thermal and magnetic properties of YFeO3 ceramic

The polycrystalline ceramic sample of YFeO3 has been synthesized by high-temperature solid-state reaction method using high-purity oxides. The formation of the compound has been confirmed by the room temperature (RT) X-ray diffraction analysis. The refined lattice parameters obtained by Rietveld analysis are: a = 5.5907 angstrom, b = 7.6082 angstrom and c = 5.2849 angstrom with orthorhombic symmetry in space group Pnma. The average grain size obtained from the SEM micrograph is around 2 mu m. The three-dimensional surface morphology has been investigated using atomic force microscopy (AFM), and the average roughness measured in the sampling area of 100.07 mu m(2) is around 142 nm. The frequency-and temperature-dependent dielectric constant has been measured. The material shows high dielectric constant value (750) at RT. The activation energy obtained from dc conductivity using Arrhenius relation sigma = sigma(o)exp(-Ea/kT) is 2.12 eV. Thermal analysis shows phase change around 625 K with minimum weight loss (i.e. 1.27% of initial weight) from RT to 1273 K. The magnetization measurement indicates soft magnetic behaviour.