Li0.5Co0.75Fe2O4 + BaTiO3 particulate composites with coupled magnetic-electric properties

Particulate composites of Li0.5Co0.75Fe2O4 and BaTiO3 with mixed structure have been synthesized by the normal ceramic method with a variation of the molar percentages. X-ray diffraction was used to carry out the structural analysis and confirm the presence of constituent phases in the composites. The dc resistivity was measured as a function of temperature and molar percentage of constituent phases. The relative dielectric constant with variation of frequency (in the range 20 Hz to 1 MHz) and temperature at four fixed frequencies (i.e. 1 kHz, 10 kHz, 100 kHz and 1 MHz) was studied. The ac conductivity was calculated from dielectric data to understand the conduction mechanism. Hysteresis measurements were carried out to determine the saturation magnetization. The variation in magnetic behaviour with the composition of constituent phases was measured as a function of the applied dc magnetic field. A maximum magnetoelectric voltage coefficient of about 372 muV cm-1 Oe-1 was observed for the (0.3)Li0.5Co0.75Fe2O4/(0.7)BaTiO3 composite. The ME conversion factor has been explained in terms of molar constitution of ferrite-ferroelectric phases and resistivity.