Synthesis of x[La0.67Sr0.33MnO3] – (1-x)[0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3] multiferroic composite with its dielectric, magnetodielectric, magnetic and electrical conductivity studies

Abstract

The present paper studies the synthesis and characterization of x[La0.67Sr0.33MnO3] – (1-x)[0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3] multiferroic composite for x = 0.1 and 0.175. Parent materials of ferroelectrics Ba0.7Ca0.3TiO3 (BCT) and BaZr0.2Ti0.8O3 (BZT) and ferrite La0.67Sr0.33MnO3 (LSMO) have been prepared via hydroxide co-precipitation method while its composite x[LSMO] – (1-x)[0.5 BCT -0.5 BZT] was synthesized by ceramic route. The presence of ferroelectric and ferrite phases were confirmed by structural studies of composites. Microstructure shows the dense and closely packed LSMO particles over BCT-BZT ferroelectric phase. The dielectric properties of composites were studied in frequency range of 1KHz-1MHz and from room temperature to 500OC. P-E hysteresis loops of composites shows noticeable values of saturation polarization (Ps) and remnant polarization (Pr). Significant value of magnetoelectric (ME) coupling coefficient (α) of 2.15mV/cmOe was observed for the composite 0.175LSMO – 0.825(0.5BCT-0.5BZT) at 1 KHz frequency. Magnetodielectric (MD) properties of the composites were investigated by measuring the magnetocapacitance up to 1 T magnetic field. MD effect can be explained on the basis of contribution of dielectric constant due to interfacial polarization which depends on magnetic field and changes due to induced stress. Frequency dependent ac conductivity was confirmed by Jonscher's Universal Power law. Temperature dependent dc conductivity of the materials shows the Arrhenius behavior. As the ferrite content of LSMO increases in the composite saturation magnetization increases which can be studied by the hysteresis plot.