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

The composites ( x )CoFe 2 O 4 –(1− x )Ba 0.8 Sr 0.2 TiO 3 are prepared by solid‐state reaction method using microwave double‐step sintering. Ba 0.8 Sr 0.2 TiO 3 crystallizes to tetragonal crystal symmetry with P4mm space group and CoFe 2 O 4 crystallizes to cubic crystal symmetry with 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 °C temperature range. Composite with x = 0.1 ( ε′ ≈ 170, tan δ = 0.08 at 1 kHz) and 0.2 ( ε ′ ≈ 390, tan δ = 0.07 at 1 kHz) has better dielectric properties than the parent Ba 0.8 Sr 0.2 TiO 3 ferroelectric ( ε ′ ≈ 125, tan δ = 0.16 at 1 kHz) and CoFe 2 O 4 ferrimagnetic phases ( ε ′ ≈ 375, tan δ = 0.72 at 1 kHz), respectively. Composite with 10% cobalt ferrite has the highest saturation polarization (2.1 μC cm −2 ), the highest remanent polarization (0.9 μC cm −2 ), and coercive field (23.9 kV cm −1 ) compared to ferroelectric phase followed by x = 0.2 composite ( P S = 1.6 μC cm −2 , P r = 0.8 μC 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 )CoFe 2 O 4 –(1−x)Ba 0.8 Sr 0.2 TiO 3 for the technological application.