HIGH-FIELD MAGNETIZATION PROCESSES IN DILUTED MAGNETIC SEMICONDUCTORS

Recent developments in the use of high magnetic fields to investigate the magnetic properties of diluted magnetic semiconductors are reviewed here. The need for high fields to obtain reliable values of the exchange interaction are described. For a summary of previous work we refer to a presentation in the Proceedings of the Honda International Symposium on the Application of High Magnetic Fields to Materials Science.1) The most straight-forward approach for extracting the exchange interaction between pairs of magnetic ions is based on the observation of steps in the magnetization vs. field data. These steps result from the magnetic-field splitting of the angular momentum states and the level crossings that occur as the magnetic field is increased.2) It has been shown, however, that, even in the absence of observable steps, it is possible to estimate the exchange interactions from a fit to an expression containing terms representing both the magnetization of individual ions and that of pairs, if the magnetic field is high enough.3) A model, based on this approach, has been developed.4) In the present review this model will be summarized and the results applied to magnetization data taken on II-VI and IV-VI diluted magnetic semiconductors.