Optical, electrical and magnetic properties of double perovskite Ba2MnTiO6 for optoelectronics applications

Abstract

The study details the synthesis of Ba2MnTiO6, a polycrystalline double perovskite, via solid-state reaction, and its subsequent characterizations. X-ray diffraction (XRD) Rietveld analysis indicates dual phase crystallization (cubic and hexagonal) in the material, with a mean crystallite size measuring 65.6 nm. Field emission scanning electron microscope with energy dispersive (FESEM-EDS), ultraviolet-visible diffuse reflectance (UV-VIS-DRS) and photoluminescence (PL) spectroscopies reveal a grain size of 2.96 mu m, a direct optical energy band gap of 1.43 eV, and violet emission at 420 nm wavelength, respectively. RAMAN and Fourier transform infrared (FTIR) spectra provide detailed insights into molecular vibrations. Dielectric spectra exhibit a peak at similar to 400 degrees C, pointing a transition from ferroelectric phase to paraelectric phase. Non-overlapping Small Polaron Tunneling (NSPT) model and Jonscher's Power law (JPL) elucidate the conduction mechanism. Impedance studies suggest the material's Negative Temperature Coefficient of Resistance (NTCR) response, while Bergman fitting of modulus spectrum describes relaxation of charge carriers, following a non-Debye pattern. Polarization-Electric field (P-E) & Magnetization- Magnetic field (M- H) loops demonstrate the material's ferroelectric and anti-ferromagnetic properties. The optical band gap value and massive dielectric constant (similar to 105) with a low loss value of the material offer promising application prospects in optoelectronics.