Dielectric, Magnetic and Surface Analytical Study of Dy and Tb Doped (Bi, Pb)(Fe,Ti)O3 Multiferroic Ceramics

Abstract

Polycrystalline samples of Bi_0.8A_0.1Pb_0.1Fe_0.9Ti_0.1O₃(where A = Dy and Tb) ceramics have been prepared through high temperature sintering technique. X-ray diffraction analysis showed that the ceramics possess perovskite phase with hexagonal crystal symmetry. Dielectric and electrical properties indicate that the Curie temperature shifted to higher temperature with Dy doping. AC conductivity of the sample increases with increase in temperature which confirms the negative temperature coefficient of resistance (NTCR) behaviour of material. Substitution of Dy and Tb ions at A-site suppress the spiral spin structure of BiFeO₃ which is further responsible for the appearance of weak ferromagnetism atroom-temperature.Induced destruction of the spin cycloid due to the Dy and Tb substitution, these multiferroic properties are attributed because of the enhanced magneto-electric interaction.