Magnetization and exchange interactions in Zn1-xFexTe diluted magnetic semiconductors

Magnetization and magnetoreflectivity measurements have been performed in d iluted Zn1-xFexTe compounds, at T = 1.8 K. The magnetization of Fe2+ ions i s quantitatively analyzed in the framework of the crystal field and spin-or bit coupling model and is in excellent agreement with the crystal field and spin-orbit coupling parameters we deduced from previous optical studies (D elta = -2693 cm(-1) and lambda = -102.2 cm(-1)). The six Zeeman-like compon ents of the free exciton spectrum are observed, in Faraday or Voigt configu ration. The comparison between the energy splittings and the magnetization data yields the values for the conduction and valence exchange parameters: N(0)alpha = 0.29 +/- 0.09 eV and N(0)beta = -1.50 +/- 0.17 eV. (C) 2000 Els evier Science Ltd. All rights reserved.