Abstract
We have measured x-ray-absorption near-edge-structure (XANES) spectra of the diluted magnetic semiconductors (Formula presented)(Formula presented)Y (Y=S, Se) and (Formula presented)(Formula presented)S alloys at the Mn and Co (Formula presented) edge. Analysis of the Mn (Formula presented)-edge XANES spectra for (Formula presented)(Formula presented)Y and Co (Formula presented)-edge spectra for (Formula presented)(Formula presented)S revealed the presence of a white-line feature in each series, whose intensity increased linearly with concentration x. The white-line feature is assigned to Mn(Co) (Formula presented) and (Formula presented)photoelectron excitations to nonbonding 3d(e) states and to the relatively broadened band of Mn (Co) 3d((Formula presented))-S 3p hybridized antibonding states for the sulfides, and to Mn 3d((Formula presented))-Se 4p hybridized states for the selenides. The rate of increase of (Formula presented) white-line intensity with x is associated with the difference in the degree of p-d hybridization of states between Mn (Co) 3d and S 3p for the sulfides, and between Mn 3d and Se 4p for the selenides. Our results indicate that the magnetic-transition-metal 3d((Formula presented))-anion p hybridization is strongest for (Formula presented)(Formula presented)S, intermediate for (Formula presented)(Formula presented)S and least for (Formula presented)(Formula presented)Se. From separate and Co K-edge extended x-ray-absorption fine-structure measurements on (Formula presented)(Formula presented)S and (Formula presented)(Formula presented)S at 77 K, we found that the nearest-neighbor (NN) Mn-S (2.42 Å) and Co-S (2.30 Å) bond lengths remained essentially constant with x in these alloys, respectively. The degree of relaxation of the NN Mn (Co)-anion bond lengths is found to be directly related to the strength of p-d hybridization coupling in these alloys.
Department(s)
Physics, Astronomy, and Materials Science
Document Type
Article
DOI
https://doi.org/10.1103/PhysRevB.55.7633
Rights Information
© 1997 The American Physical Society
Publication Date
1-1-1997
Recommended Citation
Pong, W. F., R. A. Mayanovic, J. K. Kao, H. H. Hsieh, J. Y. Pieh, Y. K. Chang, K. C. Kuo, P. K. Tseng, and J. F. Lee. "Degree of pd hybridization in Zn 1− x Mn x Y (Y= S, Se) and Zn 1− x Co x S alloysas studied by x-ray-absorption spectroscopy." Physical Review B 55, no. 12 (1997): 7633.
Journal Title
Physical Review B - Condensed Matter and Materials Physics
