Structural and Dielectric Analysis of La_0.88Bi_0.12Mn₀.₈₀Ni_0.20O₃ Composite

Abstract

Composite La0.88Bi0.12Mn0.80Ni0.20O3 was synthesized using the conventional solid-state reaction method with sintering temperature of 1200 °C for 12 hours and the dielectric properties investigated. The X-ray diffraction result shows that the composite has a rhombohedral structure with lattice parameter of a = b = c = 5.5136 Ǻ. Scanning electron microscope shows grains with approximately from 0.8 to 5.4 μm in size with presence of voids. The dielectric permittivity, εʹ and dielectric loss, εʺ were measured in the range of 298 K to 473 K where both are temperature and frequency dependent. At 1 kHz to 100 kHz, the εʹ is around 10000 and the dielectric loss tangent, tan δ is below 1.5. The electric behavior of this composite is best represented by Quasi-dc model which consists of two universal capacitors in parallel. Parameters value from the fitting indicated that high correlations of electrons between inter and intra-clusters. The activation energy, Ea calculated from the conductivity of the sample gives a value of 0.116 eV. Vibrating sample magnetometer shows that the La0.88Bi0.12Mn0.80Ni0.20O3 has a magnetic coercivity, Hc of 36.109 G and retentivity, Br, valued 2.7504 x 10-3 emu/g.