Curie-temperature dependence of microwave heating behavior of NixZn(1−x)Fe2O4 powders

• Main Authors: K. Kashimura, T. Namioka, T. Miyata, T. Fujii, H. Itoh, H. Fukushima
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2020-04-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.5134836

Recently, the microwave well absorber goes noticed as a heating aid to establish a microwave chemical plant. We determine the mechanism of the rapid and selective heating of magnetic conductive particles by electric and magnetic microwave fields. Furthermore, we investigate the dependencies of the Curie temperature of NixZn(1−x)Fe2O4 powders on their heating behaviors by employing a conventional microwave oven. In these experiments, the maximum microwave heating temperature increases with the Curie temperature of ferrites. To investigate the dependence of the microwave magnetic field strength on the heating behavior, we focus a pure magnetic field separated from 2.45 GHz microwaves onto these ferrites, and the magnetic field enhanced by a single-mode cavity is used to heat the ferrites at higher Curie temperatures. Our results indicate that there are two types of energy interactions between the ferrites and the microwave magnetic field with two different mechanisms: magnetic loss and eddy current heating. Furthermore, the heating performance of the ferrites as microwave absorbers is evaluated in comparison with SiC, which is a typical microwave absorber used in microwave processing. We believe that our findings can contribute to further advancements in microwave chemistry and related fields.