Hard Ferrites for Permanent Magnets
Rohit Jasrotia
Abstract
The hard ferrites called hexaferrites or hexagonal ferrites show excellent characteristics which makes them suitable for many potential applications. The magnetic characteristics of these hexaferrites must be tweaked to meet the needs of a certain potential application. This can be fulfilled by making few modifications within the crystal structure of hexagonal ferrites such as reduction of the size at the nanoscale, changes in the morphology, substitution of divalent as well as trivalent metal cations for increasing magnetization, and many more. In the current chapter, the requirement for excellent hexaferrite-based magnets, we evaluate the most promising ways for improving the performance of hexaferrite-based materials for utilization in permanent magnets, as well as their latest results. Then, we have provided a comprehensive study on the suggested modifications such as size reduction, substitution, shape and many more, which helps in the improvement of magnetic characteristics of hexagonal ferrites for their commercial use for permanent magnets application. Lastly, the concluding remarks have been presented.