The hexagonal ferrites, also known as hexaferrites, have become massively important materials commercially and technologically, accounting for the bulk of the total magnetic materials manufactured globally, and they have a multitude of uses and applications. As well as their use as permanent magnets, common applications are as magnetic recording and data storage materials, and as components in electrical devices, particularly those operating at microwave/GHz frequencies for mobile and wireless communications, electromagnetic wave absorbers for electromagnetic compatibility (EMC), radar absorbing materials (RAM) and stealth technologies. One of the most exciting recent developments has been the discovery of single phase magnetoelectric/multiferroic hexaferrites,
IntroductionThe hexagonal ferrites are magnetic iron(III)-based oxides with a hexagonal crystal structure (Fig. 7.1), also known as hexaferrites. They have become massively important materials commercially and technologically, and hexaferrites are used in a multitude of applications, for example permanent magnets, electrical motors and transformers, actuators and sensors, information storage, mobile communications, transport, security, defence and aerospace [1]. M-type hexaferrites account for over 90 % of the total permanent magnetic materials