Raman spectroscopy and enhanced magnetic and dielectric properties of Pr and Ti codoped BiFeO₃ ceramics

In this work, we have investigated the interplay between structure, magnetic and dielectric properties of (Bi_1−xPr_x)(Fe_1−xTi_x)O₃ ceramics (x = 0.03, 0.06 and 0.10) synthesised via solid state reaction method. X-ray diffraction and Raman studies exhibited the structural transition from rhombohedral to orthorhombic phase for higher codoping concentration. Room and low temperatures weak ferromagnetic behaviour has been established from the splitting between field cooled and zero field cooled curves and electron spin resonance spectra. This weak ferromagnetism increases with increasing codoping concentration. X-ray photoelectron spectroscopy showed valence fluctuation between Fe³⁺/Fe²⁺ ions for lower codoping concentration while only Fe³⁺ ions are observed for higher codoping concentrations. The observed dielectric anomaly near Neel temperature becomes more prominent with increasing codoping which indicates the enhancement of magnetic and electric interactions. A correlation between shifts of Neel temperature with variation of Fe–O–Fe bond angle has been observed.