INFLUENCE OF PAIR-EXCHANGE INTERACTION ON THE MAGNETIZATION OF IV-VI-COMPOUND DILUTED MAGNETIC SEMICONDUCTORS

The magnetization of IV-VI-compound diluted magnetic semiconductor systems has been measured at 4.2 K with use of the sample-extraction method in steady magnetic fields up to 30 T. The results have been fitted by an expression containing a Brillouin function, representing isolated magnetic ions, plus a term representing pair interactions. The fitting parameters are x-1, the effective occupation probability of a cation site by a Mn ion; T0, representing the exchange interaction between Mn2+ ions; x-2, representing the number of Mn2+ ions in pairs; and JP, a pair-exchange parameter. Reasonable agreement of these high-field parameters with parameters obtained from the low-field susceptibility was obtained. Fits including the nearest-neighbor-pair exchange function confirm the importance of nearest-neighbor pairs in the antiferromagnetic exchange interaction. © 1990 The American Physical Society.