Magnetodielectric effect in BaTiO3/ZnFe2O4 core/shell nanoparticles

• Synthesis of BaTiO3/ZnFe2O4 core/shell nanoparticles.
• Nanoparticles are ferromagnetic with spontaneous magnetization of 8 emu/g.
• Dielectric constant is found to increase with temperature.
• About 1.3% change, in dielectric constant at 1 T of magnetic field.

BaTiO3(perovskite)/ZnFe2O4(ferrite) core/shell nanoparticles could be facilely synthesized via combined co-precipitation and sonochemical approach in an optimized condition. X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and vibrating sample magnetometer (VSM) option in a physical property measurement system were employed to investigate the structural and magnetic properties, respectively, of the synthesized nanoparticles. Magnetic studies revealed that the system is ferromagnetic with spontaneous magnetization of 8 emu/g. This is attributed to the cationic redistribution in octahedral and tetrahedral crystallite sites of ZnFe2O4. The resulting core/shell nanoparticles were transformed in a parallel plate capacitor and the variation of dielectric constant with temperature from 20 K to 300 K, at frequencies 1 kHz, 10 kHz, 100 kHz, 500 kHz and 1 MHz were recorded. The increase in dielectric constant with temperature was observed for all the frequencies along with the shifting of dielectric maximum towards higher temperature with increase in frequencies. At high frequency (1 MHz), a change of 1.3% in dielectric constant under the influence of 1 T external magnetic field has been observed in this core/shell system and might be interesting for possible applications.