Physical Review B 76,3 (2007) 035209;
Zn1-xFexTe, a zinc blende II-VI diluted magnetic semiconductor (DMS), exhibits a temperature independent magnetization at low temperature (van Vleck paramagnetism) as a consequence of the electronic structure of Fe2+ in its site symmetry as an isoelectronic replacement of Zn2+. The lowest level of its (5)Gamma(3) ground state multiplet has a Gamma(1) nonmagnetic level, with a Gamma(4) magnetic level 2.26 meV above it. The Raman spectrum of this DMS displays the Gamma(1)->Gamma(4) electronic transition (labeled in this paper Gamma(1 -> 4)), whose Zeeman splitting is interpreted in terms of symmetry considerations and numerical calculations. The magnetic field and temperature dependence of the spin-flip Raman line (omega(SFR)) of the donor-bound electron in Zn1-xFexTe exhibit characteristics typical of the van Vleck paramagnetism and, in combination with magnetization measurements, yield the s-d exchange constant N-0 alpha=239.0 +/- 10 meV. The Raman spectra also show Gamma(1 -> 4) in combination with the LO phonons of Zn1-xFexTe as a ternary alloy with an intermediate mode behavior.
Physics, Condensed Matter
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