Review of Irradiation Effects on Ferrites : Results in the World from 1970 to 1995

Abstract
In this paper, we present the main irradiation effects observed on ferrites in the world between 1970 and 1995. The crystallographic and magnetic changes induced by irradiation are shown for various kinds of particles : fast neutrons, low energy ions and high energy heavy ions and for different ferrite structures : spinels, garnets and hexaferrites.The observed effects depend both on the mechanism of particle crystal interaction and on the structure of the ferrite. From crystalline point of view, several effects can be induced : increase of lattice parameter, change of site and valence for cations and anions, amorphisation, creation of tracks showing either elongated extended defects or continuous amorphous cylinders. From magnetic point of view, the following effects can be induced : - the magnetization and the Curie temperature can either increase, or decrease, or be constant, - the anisotropy can change and even cancel. These effects are reproducible and stable at 300K. Recently, it was found that Fe₃O₄ is the most irradiation resistant ferrite.