Effect of sintering temperature and soaking time on the magnetic properties and transmission behavior of nano crystalline Mg0.8Mn0.2Al0.1Fe1.9O4.

In this study, Mg–Mn–Al ferrite with a chemical composition of Mg_0.8Mn_0.2Al_0.1Fe_1.9O₄ was synthesized via the sol–gel auto-combustion method. The effects of the sintering time and temperature on the magnetic properties and transmission behaviors were investigated in detail. X-ray diffraction (XRD) results revealed that the powders in the as auto-combusted state were in an amorphous state. Moreover, based on the differential thermal analysis (DTA) curve, the calcination temperature was calculated to be ~900 °C. According to the Archimedes equation, the highest density was obtained for the specimen sintered at 1250 °C for 5 h (94% of the theoretical density). In addition, permagraph results revealed the average magnetic properties of the mentioned samples are as follows: H_c = 7.0 Oe and M_s = 1400 G. According to vector network analyzer (VNA) results, the samples with qualified transmission behaviors showed low scattering parameters in a wide range of frequencies. Highlights: Nanocrystalline Mg_0.8Mn_0.2Al_0.1Fe_1.9O₄ was formed via a sol–gel auto-combustion method. Microstructural, magnetic, and transmission behaviors (TB) were investigated. The maximum density was obtained for the sample sintered at 1250 °C for 5 h (~4.08 g/cm³). The TB of the samples was improved by increasing Ms. The most favorable TB was obtained for the sample sintered at 1250 °C for 5 h. [ABSTRACT FROM AUTHOR]