Synthesis optimization and investigation on electrical properties of Fe~(+2)-doped Mg_2TiO_4 ceramics for energy storage

摘要

Polycrystalline MgFeTiO_4 ceramic is prepared using a solid-state reaction route. The structural, vibrational, morphology, and electrical characteristics of the compound are studied. Crystal structure and phase analysis results suggest that MgFeTiO_4 has a cubic spinel structure corresponding to the Fd3m space group. Fourier transform infrared (FTIR) and Raman spectroscopy indicate that Mg-O, Fe-O, and Ti-O bonds are present in the sample. X-ray photoelectron spectroscopy study suggests the valence state of iron (Fe); thus, the formation of MgFeTiO_4 is confirmed. The morphology and compositional analyses are done by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The electrical and dielectric behaviors of the sample are studied at various temperature ranges. The dc conductivity of 5.68× 10~(-4) S cm~(-1) is obtained at 300 °C, which is higher compared to LiFeTiO_4. The activation energy is estimated and observed two different temperature-dependent conductivity regions.