Extended X-Ray Absorption Fine Structure Studies of Co Doped ZnS and ZnSe Alloys |
| K. Ławniczak-Jabłońska and Z. Gołacki Institute of Physics, Polish Academy of Science, Al. Lotników, 02-668 Warszawa, Poland |
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| X-ray absorption experiments were performed at the Kedge of Co and Zn in Zn1-xCoxS and Zn1-nCoxSe compounds with x = 0.25, 0.16, 0.10, 0.05, 0.00 in the sulphides samples and x = 0.07, 0.02, 0.00 in the selenide ones. Analysis of the extended X-ray absorption fine structure oscillations using phase and amplitudes either from McKale code or from standard samples, gave the distance, number of atoms and the Debye-Waller factors for nearest neighbours. We found that the cation-anion distances Zn-S(Se) or Co-S(Se) are systematically shorter in ZnS than in ZnSe matrix, the Zn-anion distance is always larger than the Co-anion one without any significant Co content dependence. This allowed us to estimate the covalent radius of Co in the studied matrices to be 0.025 Å smaller than the Zn covalent radius and stated that covalent radius of Co is independent of the type of surrounding atoms. In addition the Debye-Waller factors indicated a better ordering in ternary compounds than in the binary standard ones in agreement with rocking curve measurements. |
| DOI: 10.12693/APhysPolA.86.727 PACS numbers: 61.10.Lx, 87.64.Fb, 78.70.Dm |