Crystal structure refinement, dielectric and magnetic properties of A-site and B-site co-substituted Bi0.90Nd0.10Fe1-xTixO3 (x=0.00, 0.02, 0.05 & 0.07) ceramics

Abstract

Nd and Ti co-doped Bi0.90Nd0.10Fe1-xTixO3 (x = 0.00, 0.02, 0.05 & 0.07) ceramics were prepared via conventional solid state reaction method. The crystal structure was investigated by X-ray diffraction at room temperature. The XRD data was further studied by Rietveld refinement using Full prof suite which revealed the structural transformation from rhombohedral (R3c) into triclinic (P1) phase. Low values of R factors and χ2 showed good agreement between experimental and refined intensities. The analysis of Raman spectra is consistent with the earlier reported data. Dielectric response of all the prepared samples was analyzed in the frequency range 100 Hz to 7 MHz at different temperatures. All the samples exhibited dispersion in dielectric constant values at lower frequencies and became nearly constant at higher frequencies. With Ti substitution, the dielectric constant became stable at higher frequencies due to suppression of oxygen vacancies. The temperature variation of dielectric constant and tanδ displayed sharp anomalies in the vicinity of Neel temperature. Impedance spectroscopy disclosed appearance of grain contributions in the prepared samples. Magnetic characterization was performed by using Vibrating sample magnetometer upto a field of 5 kOe at room temperature. The hysteresis loop exhibited inherent antiferromagnetism with a weak ferromagnetism. The maximum remnant magnetization (Mr) is observed for Bi0.90Nd0.10Fe0.95Ti0.05O3 is 3.15 memu/g and the corresponding value of coercive field is 130.65 Oe.