Crystal structure transition and multiferroic properties in Bi1-xHoxFeO3 (x = 0.05, 0.10, 0.15, & 0.20) ceramic by rietveld analysis

Bi1-xHoxFeO3 multiferroics (with x = 0.05, 0.10, 0.15, & 0.20) were synthesized via conventional solid state reaction method. X-ray patterns recorded by powder diffraction method depicts change in crystal structure at concentration x = 0.20. Rietveld refinement of the XRD patterns deduce the stabilisation of rhombohedral R3c phase upto concentration x = 0.15, while for concentration x = 0.20, the mixed phase model including rhombohedral R3c and orthorhombic Pnma space group was established to give the best fitting. Dielectric behaviour of all prepared ceramic samples was carried by impedance / gain phase analyser within the frequency range from 100Hz to 7MHz at different temperatures. The electron density contours obtained by G-Fourier program of Fullprof suite deduced the smooth spread of diffracting elements throughout the refinement simulated crystal structure. The change in crystal structure is attributed to the distortion of FeO6 octahedra via doping of Ho at phase boundaries.