Magnetic and Dielectric Properties of Multiferroic Bi_1-xGd_xFeO₃

Abstract

Bi_1-xGd_xFeO₃ (0≤x≤1.0) nanoparticles with an average diameter of 18 to 47 nm were synthesized by a wet chemical method. The annealing temperatures were controlled to obtain single-phase Bi_1-xGd_xFeO₃ nanoparticles. The crystal structures changed from rhombohedral to orthorhombic as Gd ions increased to around x=0.2. The behavior of magnetization curves of x=0.1 suggested canted antiferromagnetism and magnetization drastically increased compared with x=0 (BiFeO₃). This suggests that the canting angle increased with the increase of Gd ion. The dielectric properties of x=0.1 showed that dielectric loss (tan δ) has been improved compared with that of x=0 (BiFeO₃) to about 90%, while real dielectric constant ε′ decreased about 15%. The reason is considered to be that impurities are restrained and leakage current decreased.