Effect of calcination temperature on structural and terahertz characterization of M-type barium ferrite

We present detailed studies on M-type barium ferrite (BaFe12O19, BaM) synthesized by the sol–gel combustion method that is calcined at 1000 °C, 1100 °C, and 1200 °C. In addition to the structural properties, we present the THz optical dielectric constant and conductivity response of this system as a function of calcination temperature. From x-ray diffraction (XRD) studies, a single-phase of the hexagonal structure is established, and the crystallite size (Dhkl) was calculated to be in the range of 26 nm–28.54 nm. The XRD patterns were analyzed to evaluate lattice parameters (a, c, V) and x-ray density (ρx). Home built terahertz time-domain spectroscopy was performed to investigate the complex refractive index (n̂s) of the samples at room temperature in a frequency range of 0.2 THz–1.2 THz. The complex dielectric constant (ε̂s) and conductivity (σ̂s) as a function of calcination temperature were deduced using THz spectroscopy data. The complex dielectric constant and conductivity of BaM were determined for the calcination temperatures of 1000 °C, 1100 °C, and 1200 °C.