Study of magnetic and dielectric properties of ZnFe2O4/CoCr2O4 nanocomposites produced using sol-gel and hydrothermal processes

Abstract

In this work, zinc ferrite (ZnFe2O4) and cobalt chromite (CoCr2O4) nanoparticles were synthesized using sol-gel process and hydrothermal method, respectively. The two different materials were mixed by physical means such that the final ratio (by weight) of the resulting nanocomposites (ZnFe2O4:CoCr2O4, abbreviated as ZF:CC) were 3ZF-CC, ZF-CC and ZF-3CC. The x-ray diffraction patterns of the ZnFe2O4 and CoCr2O4 nanoparticles confirmed the formation of the spinel structure, whereas the average crystallite size values computed using the Scherrer equation were found to be 43 and 57 nm, respectively. Scanning electron microscope (SEM) examination of the nanocomposites confirmed the nonspherical shape of the nanoparticles, homogenous dispersion, and larger grain size. The phase pure spinel structures of ZnFe2O4 and CoCr2O4 was confirmed from the fourier transform infrared spectroscopy (FTIR) analysis. Also, the composites formation did not influence any change in the functional groups. The dielectric properties, determined using LCR meter, exhibited non-repetitive behavior for the ZF-CC composite. The significant increase in the dielectric constant value was observed as the Fe2+↔Fe3+ and Cr2+↔Cr3+ transition due to electron transfer plays vital role in low frequency region, Also, explained by Maxwell-Wagner model. Moreover, the variation in experimental magnetic moments of ZF, CC and their nanocomposites (ZF-3CC, ZF-CC,3ZF-CC) were studied. VSM results revealed the change in behavior of magnetic nature of materials appreciably from pristine as magnetization was increasing and coercivity was decreasing with CC component and finally an optimized magnetic parameter values (Ms =51.20 emu/g and Hc =200 Oe) at ZF-CC were obtained.