LIQUID-NITROGEN TEMPERATURE REFLECTIVITY SPECTRA OF ZN1-XMNXSE AND ZN1-YFEYSE MIXED-CRYSTALS

The Liquid nitrogen temperature reflectivity spectra of the tetrahedra l diluted magnetic semiconductors (DMS's) Zn1-yFeySe and Zn1-xMnxSe cr ystallizing in the zinc-blende structure were investigated. The reflec tivity measurements for different concentration of Fe (y = 0.01, 0.05, and 0.10) and Mn (x = 0.10 and 0.30) ions were taken out in a wide en ergy range between 4 and 30 eV using synchrotron-radiation from ADONE storage ring in Frascati. The average resolution Delta E/E used for th ese measurements was better than 1 x 10(-3) over the entire spectral r ange. The single crystals were cleaved, before being mounted inside th e reflectometer, from the samples grown by the Bridgman method. The co mparison between the reflectivity spectra of ternary systems and host crystal ZnSe is made. The changes of the structures of reflectivity sp ectra of host crystal ZnSe caused by the influence of Fe and Mn ions a re discussed.