Structure, magnetic and dielectric properties of nanocrystalline Se-xFe

Abstract

Nanocrystalline Se-xFe (x = 3 and 5 wt%) samples were prepared by solid state reaction. XRD revealed the presence of two phases; FeSe2 and Se. HRTEM showed the epitaxial growth of FeSe2 on Se. The magnetization measurements showed ferromagnetic behavior above room temperature for sample with x = 5 wt%. The a.c. conductivity for x = 3 wt% follows the overlapping large polaron tunneling model, while for (x = 5 wt%) sample it follows the correlated barrier hoping model. The temperature dependence of the dielectric measurements revealed an anomaly above room temperature for (x = 5 wt%) sample, while it appeared at room temperature for (x = 3 wt%) sample. © 2014 Elsevier Ltd. All rights reserved.