Issue Description


Authors : Ekta Chaturvedi1, K. G. Rewatkar2, V. M. Nanoti3

Page Nos : 145-153

Description :
Abstract: The partially substituted M-type strontium ferrite (SrFe12O19) with concentration ratio of chain structure of Sr(Ni-Ir)xFe12-2xO19 (x = 0.02 and 0.09) has been prepared using sol-gel auto combustion route by blending accompanied with fuels as urea as reducing agent. The influence of the composition on both structural and electrical properties of samples is emphasized. The powders were characterized for morphological behaviour with XRD, SEM, EDX and electrical characteristics with Impedance Analyzer. The substituted compound showed M-phase with space group P63/mmc, verified from diffraction pattern. SEM showing the formation of hexaferrite disk shape with average grain size of 22 nm - 61 nm which is further confirmed by TEM results. In this paper the variation of dielectric constant, dielectric loss, tangent loss and dc conductivity etc of the sample has been investigated. The migration of Fe3+ ion from octahedral site to tetrahedral site decreases the dielectric constant with increase in Ni-Ir concentration. Activation energies were calculated at both ferromagnetic and paramagnetic region. It is found that the activation energy in the paramagnetic region is higher than that in the ferromagnetic region. The enhanced resistivity of Ni-Ir substituted strontium hexaferrite is a prospective application in microwave devices. Keywords: Sol–gel auto-combustion, magnetoplumbite, EDX, Dielectric loss, Activation Energy etc.

Date of Online: 30 Sep 2014