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arXiv · 1512.03889

Complex dielectric and impedance behavior of magnetoelectric Fe2TiO5

Shivani Sharma·Tathamay Basu·Aga Shahee·K. Singh·N. P. Lalla·E. V. Sampathkumaran
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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.

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Shivani Sharma, Tathamay Basu, Aga Shahee, K. Singh, N. P. Lalla, E. V. Sampathkumaran. 2015-12-12. Complex dielectric and impedance behavior of magnetoelectric Fe2TiO5. https://doi.org/10.1016/j.jallcom.2015.12.090

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