Crystal Structure, Magnetic, and Dielectric Properties of (x)CoFe2O4-(1-x)Ba0.8Sr0.2TiO3 Multiferroics

The composites (x)CoFe2O4-(1-x)Ba0.8Sr0.2TiO3 are prepared by solid-state reaction method using microwave double-step sintering. Ba0.8Sr0.2TiO3 crystallizes to tetragonal crystal symmetry with P4mm space group and CoFe2O4 crystallizes to cubic crystal symmetry with Fd3 over bar m space group. Electron microscopy techniques are used to understand the microstructure, elemental composition, and morphology of the composites. The dielectric properties are measured in the 1 Hz-1 MHz frequency range and 40-400 & DEG;C temperature range. Composite with x = 0.1 (& epsilon;& PRIME; & AP; 170, tan & delta; = 0.08 at 1 kHz) and 0.2 (& epsilon;& PRIME; & AP; 390, tan & delta; = 0.07 at 1 kHz) has better dielectric properties than the parent Ba0.8Sr0.2TiO3 ferroelectric (& epsilon;& PRIME; & AP; 125, tan & delta; = 0.16 at 1 kHz) and CoFe2O4 ferrimagnetic phases (& epsilon;& PRIME; & AP; 375, tan & delta; = 0.72 at 1 kHz), respectively. Composite with 10% cobalt ferrite has the highest saturation polarization (2.1 & mu;C cm(-2)), the highest remanent polarization (0.9 & mu;C cm(-2)), and coercive field (23.9 kV cm(-1)) compared to ferroelectric phase followed by x = 0.2 composite (P-S = 1.6 & mu;C cm(-2), P-r = 0.8 & mu;C cm(-2), and E-C = 19.2 kV cm(-1)). Composite with x = 0.2 shows the highest magnetic coercive field of 1.96 kOe. Hence, this article advocates that 20% ferrite in the composites is the optimized composition for multiferroic applications. The present study will help to explore piezoelectric, magnetostrictive, and magnetoelectric properties of (x)CoFe2O4-(1-x)Ba0.8Sr0.2TiO3 for the technological application.