Modifying the structure and dielectric characteristics of MnFe<inf>2</inf>O<inf>4</inf>/ZnMn<inf>2</inf>O<inf>4</inf> heterostructure nanocomposites via changing the composition

Abstract

Heterostructure nanocomposite (1−x)MnFe2O4/xZnMn2O4 (x = 0, 0.2, 0.5, 0.8, 1) samples were prepared using the sol-gel method. Utilizing the measured x-ray diffraction patterns and Rietveld analysis, the effect of alloying parameter (x) on the formed phases, their crystal structure, microstructure, cation distribution and bond lengths was investigated for each sample. The analysis demonstrated that for x = 0.2, 0.5, the nanocomposites comprised both MnFe2O4(MFO) and ZnMn2O4(ZMO) phases, while for x = 0.8 only ZMO phase is formed. Analysis also disclosed the exchange of cations between the octahedral and tetrahedral sites of the two phases. The effect of alloying parameter (x), the frequency and temperature on the dielectric permittivity, dielectric loss, complex impedance, electric modulus, and ac conductivity was explored in detail. The sample with x = 0.5 exhibited ferroelectric characteristics. The different conductivity mechanism in each sample was also investigated. Sample with x = 0.5 has a semiconductor nature in all temperature ranges while other samples have metal and semiconductor characteristics depended on the measured temperature region. [Figure not available: see fulltext.].