X-RAY NEAR-EDGE STRUCTURE-ANALYSIS OF ZNSE, ZNMNSE AND ZNFESE - EXPERIMENTAL AND THEORETICAL-STUDIES

Experimental studies of x-ray absorption edges have been carried out i n ZnSe, Zn1-xMnxSe (x = 0.05 and 0.1) and Zn1-xFexSe (x = 0.22) for th e K edges of Se, Zn, Mn and Fe. A comparison is made for a zincblende (ZB) crystalline structure of ZnSe, ZnMnSe and ZnFeSe with calculated results from electron densities of states in the conduction band of th ese materials obtained from a band calculation of the ferromagnetic ph ase of Zn1-xMnxSe (x = 0.5) and Zn1-xFexSe (x = 0.25) using the LMTO m ethod. The agreement between the theoretical x-ray absorption edges an d experimental data is satisfactory. Further, a comparison based on th e density of states for ferromagnetic and antiferromagnetic ordering h as been carried out in the case of ZnFeSe. Using the virtual crystal m odel for ZnFeSe and ZnMnSe, the Se K edges of the hypothetical zincble nde structure of FeSe and MnSe as well as a hybridized contribution of FeSe and MnSe in ZnFeSe and ZnMnSe have been extracted. Comparing the data with the conduction band of pure ZnSe, taken as a standard compo und, these show a maximum of the p-like contribution in ZnFeSe situate d at about 1.7 eV (maximum A) below, and 9.6 eV (maximum B) above, the corresponding energy of the conduction band minimum for ZnSe, and at about 0.65 eV below and 11.8 eV above it for ZnMnSe.