Multiferroic properties of NiFe2O4-Ba0.7Ca0.3TiO3 nanocomposites

In this report, we present results on the multiferroic properties of four nanocomposite samples of NiFe2O4-Ba0.7Ca0.3TiO3 (NFO/BCTO), which were fabricated through combinations of high-energy ball milling, heat treatment, and spark plasma sintering techniques. Structural analyses revealed that these samples simultaneously contain two phases of nano-sized NiFe2O4 (NFO) and Ba0.7Ca0.3TiO3 (BCTO) crystals. The addition of NFO into the BCTO-host did not alter the crystal structure but significantly improved the multiferroic characteristics compared to pure BCTO. Furthermore, variations in saturation magnetization (Ms) and coercivity (Hc) were investigated as a function of temperature. The results showed that Ms increased gradually with the concentration of NFO. In terms of temperature dependence, Ms(T) data deviated from the Bloch’s law with an exponent coefficient α changing in the range of 1.8–1.9, decreasing gradually as the NFO concentration increased. Meanwhile, Hc decreased gradually as the NFO concentration increased and followed the Kneller’s law in terms of temperature dependence.