Control of dielectric properties in bismuth ferrite multiferroic by compacting pressure

Abstract

Single-phase lanthanum-modified bismuth ferrite multiferroic ceramics have been synthesized by the rapid liquid-phase sintering (RLS) method. Phase composition, crystal structure, microstructure and dielectric properties of the Bi0·9La0·1FeO3 multiferroic have been studied using TG/DTA, XRD, SEM, capacitive and composite dielectric resonator methods. It has been established that the optimal conditions for formation of a perovskite Bi0·9La0·1FeO3 structure are 850 °C after 5 min in air. It has been found that the compacting pressure of the initial mixture of precursors from 90 to 1090 MPa can change the dielectric constant by ~25% in the low-frequency range and by ~80% in the microwave range up to complete elimination of the elastic polarization mechanism. The use of the RLS method under various compacting pressures opens additional possibilities for creating multifunctional multiferroics with controlled magnetoelectric coupling.