Structural, ferromagnetic, electrical, and dielectric relaxor properties of BaTiO3 and CoFe2O4 bulk, nanoparticles, and nanocomposites materials for electronic devices

Barium titanate (BaTiO3, BTO) and cobalt ferrite (CoFe2O4, CFO) nanoparticles, bulk, and nanocomposites samples were synthesized at optimized parameters using the chemical route. Structural studies revealed that all the samples showed a single-phase structure. The value of activation energy in the case of nanocomposites was 975 meV, while it was 1.58 eV and 1.0 eV for BTO and CFO-nanoparticles, respectively. We observed that the saturation magnetization and remanence of the CFO-nano sample were three times greater than the 0.3CFO–0.7BTO nanocomposite. At 10 kHz, the dielectric constants are measured 4500 (BTO-bulk), 1550 (BTO-nano), 820 (CFO-bulk), 275 (CFO-nano), and 375 (BTO–CFO nanocomposites) for a various sample of series. We found at 10 kHz, the transition from ferroelectric to paraelectric in the case of BTO-nano (Tc = 363 °C) and CFO-nano (Tc = 212 °C), while nanocomposite BTO–CFO initial change phases from ferroelectric to anti-ferroelectric (relaxor behavior) at Td = 312 °C and then from anti-ferroelectric to paraelectric (Tm > 400 °C). Similarly, in the case of CFO-bulk, we noticed Tm = 204 °C (ferroelectric to anti-ferroelectric) and Tm = 314 °C (anti-ferroelectric to paraelectric). Overall, we concluded from these studies and data that nanocomposite 0.7BaTiO3–0.3CoFe2O4 and CFO-bulk sample showed relaxor behavior as well along with the transformation change from ferroelectric to paraelectric. While BTO-nano and CFO-nano and BTO-bulk showed their transformation direct from ferroelectric to paraelectric. These simultaneous ferromagnetic and ferroelectric (dielectric) measurements confirmed the presence of multiferroic properties in our nanocomposite as well as CFO-nano and CFO-bulk systems. These proposed materials may be useful for ferroelectric and data storage devices.