Reflectance difference spectroscopy of Mn intra-ion transitions in p-dopeddiluted magnetic semiconductors

By performing in-situ reflectance difference spectroscopy (RDS) during and upon the epitaxial growth of the diluted magnetic semiconductor ZnMnTe heav ily p-doped with N, it was possible to observe below and in the band gap re gion features occurring from intra-Mn d-level transitions. Since Mn on subs titutional Zn sites is in a cubic environment and RDS measures the differen ce between the reflectances of light polarized along the two in-plane eigen states, these transitions are detectable because of the breaking, of the C- 4 rotational symmetry. In undoped materials the spectroscopic window for ob servation may open only for high values of the magnetic ion concentration, whereas in doped crystals it was possible to detect the transitions at grow th temperature and at Mn concentrations as low as 2%.