Abstract
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.
Highlights
M-type barium ferrite (BaFe12O19, BaM) is a widely known permanent magnet due to its uniaxial magnetic anisotropy along the c-axis of its crystal structure
We focused on the sol–gel combustion method that has the advantages of low energy consumption, fast synthesis process, and high purity of the product
The x-ray diffraction (XRD) data of the samples were matched with the standard patterns (ICDD: 430002)
Summary
M-type barium ferrite (BaFe12O19, BaM) is a widely known permanent magnet due to its uniaxial magnetic anisotropy along the c-axis of its crystal structure. The unit cell of BaM with a hexagonal magnetoplumbite crystal structure contains two formula units of. BaM crystallizes in a hexagonal structure with 64 ions (2Ba2+, 24Fe3+, and 38O2−) per unit cell on 11 dissimilar symmetry sites. The possibility of realizing a seemingly infinite number of compounds that exhibit widely varying magnetic properties due to the arrangement of divalent and trivalent metallic cations in the interstitial sites of the closely packed oxygen ion layers makes them very interesting. Among different classes of hexagonal ferrites, the properties of BaM are interesting as it is used in numerous applications, such as permanent magnets, recording media, military weapons, switching, microwave absorbers, and antennae.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
