Crystal structure, leakage conduction mechanism evolution and enhanced multiferroic properties in Y-doped BiFeO₃ ceramics

Ceramics of pure phase Yttrium (Y) doped BiFeO₃ prepared by a solid-state sintering route were characterized by X-ray diffraction, Raman spectroscopy, magnetic and electrical measurements. The results and analysis show that Y substitution greatly reduces the leakage current and enhances the multiferroic properties of BiFeO₃. Leakage conduction mechanism is shown to change from space-charge-limited conduction type in pure BiFeO₃ to a Poole–Frenkel emission behavior in Bi_0.90Y_0.10FeO₃. A Fowler-Nordheim tunneling mechanism in Bi_0.95Y_0.05FeO₃ ceramic is also evidenced under high electric fields. At the same time, enhanced magnetic properties due to Y-doping are confirmed by temperature dependent magnetometry and supported by Raman spectroscopy. An unexpected and sharp switching behavior in the magnetization under low magnetic fields observed in Bi_0.90Y_0.10FeO₃ ceramic, together with its improved ferroelectric property, may trigger such system for promising magneto-electric applications.