Investigation of the structural, electrical and magnetic properties of mn-doped AlFeO3

Abstract

Combining different physical properties into one material is promising for the creation of multifunctional materials. AlFeO3 (AFO) and Al(Fe0.98Mn0.02)O3 (AMFO), lead-free perovskite materials, have been synthesized by solid-state reaction technique using planetary ball milling process, and their structural, electrical, and magnetic properties were investigated by X-ray diffraction (XRD) technique, Field emission scanning electron microscope (FESEM), Vibrating sample magnetometer and impedance analyzer. XRD analysis shows that synthesized samples have rhombohedral symmetry with space group R-3c. FESEM image shows that grains are segregated into different clusters with a size distribution from 183 to 320 nm. All the samples display a decreasing trend in the real and imaginary part of the dielectric constant with increasing frequency which is due to the reduction of space charge polarization. At higher frequencies, dielectric loss is low due to inhibition of domain wall motion. At room temperature, the initial increase in the real part of permeability (µ′) is attributed to the combined effect of magnetic dipolar orientations and spin rotation. At 77 K, sudden falls of µ′ originate from the damping mechanism of spins. The imaginary part of permeability decreases exponentially with increasing frequency. In DC magnetization measurements, both AFO and AFMO show antiferromagnetic nature at room temperature.