Enhanced electrical and magnetic properties in BZT/NFO multiferroic composites derived by MARH

Abstract

Multiferroic materials comprising of ferroelectric (FE) and ferromagnetic (FM) composites exhibits added functionalities significant from scientific and technological standouts. But these FE/FM composites are very sensitive to processing parameters, sintering, and chemical modifications. In present work FE/FM composites (1 − x)(Ba Zr0.15, Ti0.85)O3–xNiFe2O4 (BZT–NFO) was sintered by microwave assisted radiant heating (MARH) technique, which has evolved as a hybrid sintering technique, where radiant and microwave sintering methods are coupled together, in such a way that, when conventional radiant heating is applied for sintering, simultaneously different (0%, 15%, 30% and 50%) Microwave power (Mw) percentages are applied in a precise and controlled manner. The present study dwells on the role of different Mw power applied during sintering on the structure, dielectric, ferroelectric and magnetic properties of (1 − x) (Ba Zr0.15, Ti0.85) O3–xNiFe2O4 (BZT–NFO) composites. Structural phase analysis carried out by X-ray diffraction displays Bragg peaks corresponding to both perovskite and ferrite phases. Since the compositional variation of ferrite remains as low as 1% for all the compositions, the overall crystal phase is dominated by perovskite phase which was further confirmed by room temperature Raman spectra. No intermediate phase or structural transitions were observed for all the compounds. Dielectric permittivity increases by 35% for the sample sintered with 15% Mw power, while leakage current decreases by an order of magnitude. At higher temperature, mobility due to oxygen vacancies/or defects present in the samples dominates the conduction mechanism. Magnetic hysteresis curve at room temperature suggests the soft magnetic nature exhibiting ferromagnetic behavior for all the samples. Sample sintered with 15 Mw power exhibits higher saturation magnetization (Ms).