Z. Naturforsch. 68a, 337 – 342
Studies of the g Factors and the Hyperfine Structure Constants for the Octahedral Interstitial Mn2+ and Cr+ Impurities in Silicon
1 School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
2 International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, P. R. China
Received July 4, 2012 / revised November 8, 2012 / published online February 6, 2013
The g factors and the hyperfine structure constants for the octahedral interstitial Mn2+ and Cr+ impurities in silicon are theoretically studied using the perturbation formulas of these parameters for an octahedral 3d5 cluster. In the calculations, both the crystal-field and charge transfer contributions are taken into account in a uniform way, and the related molecular orbital coefficients are quantitatively determined from the cluster approach. The theoretical g factors and the hyperfine structure constants are in good agreement with the experimental data. The charge transfer contribution to the g-shift (≈ g − gs, where gs ≈ 2.0023 is the spin only value) is opposite (positive) in sign and about 51–116 % in magnitude as compared with the crystal-field one for Mn2+ and Cr+, respectively. Nevertheless, the charge transfer contribution to the hyperfine structure constant has the same sign and about 12–19 % that of the crystal-field one. Importance of the charge transfer contribution shows the order Cr+< Mn2+ due to increase of the impurity valence state in the same host, especially for the g factor.
Key words: Electron Paramagnetic Resonance; Defect and Impurities; Mn2+; Cr+; Silicon.