(2) Preparation and characterization of Bi0.9M0.05N0.05FeO3 (M = Sm, Gd; N = Sr, Y) polycrystalline multiferroic compounds
Abstract:
The multiferroic compounds Bi0.9Gd0.05Sr0.05FeO3, Bi0.9Sm0.05Sr0.05FeO3, Bi0.9Gd0.05Y0.05FeO3, and Bi0.9Sm0.05Y0.05FeO3 were prepared by the conventional ceramic method and were characterized by X-ray diffraction , Fourier transform infrared spectroscopy, vibrating sample magnetometry , and differential scanning calorimetry.
The compounds were found to have the rhombohedral perovskite-like structure, accompanied by the existence of small amounts of Bi2Fe4O9 and Bi25FeO40 impurity phases.
The appearance of weak ferromagnetism in Bi0.9Gd0.05Sr0.05FeO3 and Bi0.9Sm0.05Sr0.05FeO3 is due to partial destruction of the spiral spin structure due to lattice distortion and oxygen vacancies. The magnetic transition temperatures of the compounds are 360 °C and 355 °C, respectively.