Structure-property relationship of GdCrO₃-modified BiFeO ₃ ceramics

Solid solutions of perovskites (1-x)BiFeO₃-xGdCrO₃ (x = 0, 0.1 and 0.2) has been synthesized under high-pressure conditions in an attempt to find magnetoelectric materials. Structural studies of these samples show a compositional-driven phase transition from rhombohedral for x = 0 to orthorhombic symmetry for x = 0.2, with a mixture of the two phases for x = 0.1. Magnetic and ferroelectric properties of these samples are shown to correlate with evolution of their structural state. The addition of GdCrO₃ in BiFeO₃ leads to a ferroelectric-paraelectric phase transition. The magnetic properties of BiFeO₃ are improved due to structural distortion and partial destruction of spiral spin structure caused by introducing GdCrO₃. The best combination of multiferroic characteristics, with remanent polarization and magnetization of 10.1 μC/cm² and 0.118 emu/g, respectively, was realized in the sample with x = 0.1. The magnetodielectric and magnetoelectric effect of these samples were evaluated.