Characterization of paramagnetic materials by low-temperature magnetization

A new method of analysis of low-temperature magnetization is presented for materials containing small amounts of randomly distributed magnetic ions. I t is shown that, in the case of noninteracting ions, the magnetic field H-e q, corresponding to the intercept of extrapolated linear parts of low- and high-field magnetization, does not depend on the magnetic entities concentr ation x and provides basic information on their magnetic moment, allowing, in turn, for a precise determination of x. It is also shown that, when the magnetic ions start to interact between themselves, H-eq shifts towards hig her fields and is closely related to the parameter T-0 entering into the mo dified Brillouin function. The usefulness of the presented method is illust rated by the analysis of results obtained for a number of dilute magnetic s emiconductors containing small amounts of transition metal ions. (C) 1999 E lsevier Science B.V. All rights reserved.