Analysis of negative magnetization and dielectric studies in holmium substituted samarium iron garnet

Abstract

We have used solid-state reaction approach for the preparation of polycrystalline samples of (Sm1-xHox)3Fe5O12(x=0.0 to 1.0) and the phase formation is verified by the refinement of X-ray diffraction patterns using Ia3‾d space group. The lattice constant is found to be decreased while the average grain size increases with Ho doping. The transition temperature (TC) for ferrimagnetic to paramagnetic state decreases from 561 K to 541 K for x=0.0 to x=1.0. Also, M−T plots demonstrate that every sample exhibit spin reorientation transition and with Ho doping the spin reorientation transition temperature (TSR) is reducing from 65K(x=0.0) to 20K(x=1.0). Interestingly, negative magnetization is observed for x=0.4 sample and is confirmed by applying different magnetic fields. Moreover, magnetic compensation is also observed in samples with x≥0.4. The Nyquist plots extracted from complex impedance spectra show the deviation from the ideal Debye type relaxation. It is observed that the dielectric constant has increased from 104 to 106 in the lower frequency zone with x varying from 0.0 to 1.0 making them a promising material for microwave applications.