Structural, dielectric, electrical and magnetic properties of multiferroic BaTiO3-NiFe2O4 composite ceramic

摘要

Structural, microscopic, magnetization, and dielectric properties of the multiferroic composite ceramics consisting of BiFeO3 (BTO)1??x??NiFe2O4 (NFO)x (x = 0.05, 0.1, 0.15, 0.2, 0.3, 0.4) prepared by conventional solid state route were investigated. The x-ray diffraction, Raman spectra, and SEM micrographs showed the presence of constituent phases in the composite. The variation of the dielectric constant with frequency in the range of 100 Hz to 1 MHz shows both, decrease in ???? and significant frequency dispersion accompanied with an increase in the loss tangent, with increase in NFO concentration in the composites. The BTO-NFO composites exhibited well-defined magnetic hysteresis loops at room temperature. The temperature variation of the magnetization showed indirect converse magneto electric coupling for the critical value (x=0.40) of the composite near the BTO phase transition (orthorhombic-tetragonal).