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 Bi0.90Y0.10FeO3. A Fowler-Nordheim tunneling mechanism in Bi0.95Y0.05FeO3 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 Bi0.90Y0.10FeO3 ceramic, together with its improved ferroelectric property, may trigger such system for promising magneto-electric applications.