ABSTRACT
MBE grown PbEuTe samples with Eu-contents between 0 and 1.7% were investigated by interband magnetoabsorption as well as by coherent anti-Stokes Raman scattering in the mid infrared. For samples with energy gaps larger than 220meV it is preferable to perform the CARS measurements with frequency doubled CO2-lasers (resonance CARS). The data were interpreted in the framework of the Mitchell & Wallis bandstructure model with the exchange interaction taken into account in mean field approximation. The magnetotransmission minima of samples with higher Eu-contents were rather broad superpositions of unresolved transitions, particularly in Voigt configuration. So CARS turned out to be important not only for the determination of the spin splittings of valence and conduction band, but also yielded more precise information on interband matrixelements. With increasing Eu content a pronounced decrease of P˔ is observed, whereas Pǁ remains constant. The exchange interaction between free carriers and localised magnetic moments of the Eu-ions is by far weaker than in Mn-based semimagnetic IV-VI compounds but of the same order of magnitude as in PbEuSe.
