Dielectric and Magnetic Studies La⁺³ doped Cobalt Nano Ferrite

Abstract

La3+ substituted cobalt ferrite nano-particles with the chemical composition LaxCoFe2-xO4 (here,x=0, 0.05, 0.1, 0.15 and 0.2) were synthesized using auto-combustion method. Structural and morphological studies were probed using X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Formation of rare-earth doped cobalt ferrite was confirmed using the X-ray diffraction studies. Average crystallite size (D) was found to be varying from 43.71nm to 55.37nm with the increase in La3+ concentration. Frequency dependent dielectric properties of synthesized samples were measured from 100 Hz to 1 MHz at room temperature using a precision HIOKI make LCR HI-TESTER. Dielectric dispersion was observed at lower frequencies for the synthesized samples. Magnetic properties were studies using Vibrating Sample Magnetometer (VSM), all the synthesized samples exhibited well defined magnetic hysteresis curves, there by confirming the magnetic behaviour of the sintered samples.

Electrical and Magnetoelectric Properties of Particulate Composites and Laminated Trilayered Thick‐Film Composites

“…Lowerfrequency dielectric behavior is attributed to space charge polarization, which is consistent with Koop's phenomenological theory. [22,23] According to this theory, the dielectric material is made of conducting grains separated by high-resistive grain boundaries, and it is also observed that grains are more active at high frequencies and grain boundaries are more at low frequencies. Small dielectric constant values at high frequencies may be caused by electron hopping between Fe 2þ and Fe 3þ ions, which cannot follow the change in the applied AC electric field.…”