Dielectric and magnetic birefringence in low‐chlorine‐doped n ‐type Zn 1– x Mn x Se

Generalized spectroscopic ellipsometry over the spectral range from 1.24 to 3.34 eV is used to investigate a set of molecular beam epitaxy grown lowchlorine‐doped n ‐type Zn 1– x Mn x Se films on (001)‐oriented GaAs for x = 0.0, 0.02, 0.14 and 0.28. We present evidence for intrinsic optical anisotropy in dependence of the Mn concentration caused by wurtzitestructure domain formation. We employ a previously established dielectric function model that accounts for band‐gap transition energy splitting in cubic semiconductors [Phys. Rev. B 60 , 16618 (1999)]. Room temperature magneto‐optic generalized ellipsometry in the Kerrconfiguration reveals the sp‐d exchange energy splitting parameters upon expanding our anisotropy model by inclusion of chiral spin‐polarized band‐to‐band transition contributions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)