Processing and characterization of Sr doped BiFeO3 multiferroic materials by high energetic milling

Multiferroic ceramics based on BiFeO3 and Sr-doped BiFeO3 have been processed by high energetic milling and later thermal treatments at reduced temperatures to synthesize the perovskite structure. Single phase materials are obtained at 800 °C, reducing the temperature needed to complete the reaction in solid state method. Ceramics with densities higher than 94% were obtained at 1000 °C, and up to 98% at 1050 °C. All the ceramics were obtained in a single thermal treatment, where synthesis, grain growth and densification take place. The addition of Sr stabilizes the BiFeO3 perovskite structure, avoiding its decomposition. Ceramics with higher dielectric permittivity and conductivity than non-doped materials are obtained, due to the increase of the amount of oxygen vacancies. It is shown for the first time that the grain boundary conductivity is increased in BiFeO3 by doping with Sr.

► Study of Bi0.60Sr0.40FeO3 materials as multiferroic materials.
► Processing by high energetic milling improves the processing of these materials.
► Reduction of synthesis and sintering temperatures.
► High grain boundary conductivity due to Sr addition is shown for the first time.