Complex dielectric and impedance behavior of magnetoelectric Fe2TiO5

Abstract

We have investigated the complex dielectric and impedance properties of magnetoelectric compound Fe2TiO5 (FTO) as a function of temperature (T) and frequency (f) to understand the grain (G) and grain boundary (Gb) contributions to its dielectric response. The temperature and frequency dependent dielectric permittivity data shows a sharp increase in permittivity above 200K accompanied with a frequency dependent peak in loss. At T less than 175K, only G contribution dominates even at lower frequency (nearly 100Hz), but for T greater than 175K, the Gb contribution starts appearing at low frequency. The value of critical frequency distinguishing these two contributions increases with increasing temperature. The observed non-Debye dielectric relaxation follows thermally activated process and is attributed to polaron hopping. Further the frequency dependence of ac conductivity follows the Jonscher power-law. The temperature dependency of critical exponent s shows that the correlated barrier hopping model is appropriate to define the conductivity mechanism of FTO in the studied temperature regime.

16 pages, 6 figures, Accepted in Journal of alloys and compounds

References in corpus (4)

• Materials with Colossal Dielectric Constant: Do They Exist?
• Near room-temperature colossal magnetodielectricity and multiglass properties in partially-disordered La2NiMnO6
• Multiglass properties and magnetoelectric coupling in uniaxial anisotropic spin-cluster-glass Fe2TiO5
• Modifications in the frustrated magnetism, oxidation state of Co and magnetoelectric coupling effects induced by a partial replacement of Ca by Gd in the spin chain compound Ca3Co2O6