Ferrimagnetic ordering of Ti4+ doped Mn1+xFe2-2xO4 (0 ≤ x ≤ 0.5) ferrites at room temperature

Abstract

We report structural, electrical and magnetic properties of Ti4+ doped Mn1+xFe2-2xO4 (0 ≤ x ≤ 0.5, x = 0.1) ferrites, synthesized through solid state reaction method and characterized using XRD, SEM, dielectric spectroscopy and ZFC, FC magnetization techniques. X-ray diffraction analysis shows that all the samples exhibit single phase nature with structural transformation from cubic spinel to tetragonal when substituted with Ti4+ ions. The dielectric constant, ε′ ε′, tan δ and σac have been studied as a function of frequency and composition at room temperature. It is observed that doping of the Ti4+ ions increases dielectric parameters (ε′, ε′, tan δ) and ac conductivity (σac) up to 10%, thereafter, all these parameters decrease with further doping. The dielectric loss shows anomalous behaviour with frequency where it exhibits Debye relaxation. The variation of dielectric properties and ac conductivity with frequency reveals that the dispersion is due to Maxwell-Wagner type of interfacial polarization in general and hopping of charge between Fe+2 and Fe+3 as well as between Mn+2 and Mn+3 ions at octahedral sites.The zero field cooled (ZFC) and field cooled (FC) magnetization study shows that up to 50% of Ti4+ doping all the samples exhibit ferrimagnetic ordering at room temperature. © 2011 American Scientific Publishers.