THE THEORETICAL INTERPRETATION OF THE shf INTERACTION OF Cr CENTRES IN ALKALI HALIDESReport as inadecuate




THE THEORETICAL INTERPRETATION OF THE shf INTERACTION OF Cr CENTRES IN ALKALI HALIDES - Download this document for free, or read online. Document in PDF available to download.



Abstract : The experimental results of the superhyperfine shf interaction in alkali halides cannot be understood on the basis of the models of covalency and overlap worked out so far. Taking into account the deformation of the Cr+ ions by excited states admixed by the cubic lattice potential the anisotropic shf interaction with nearest neighbours is explained without adapted parameters. The contribution of the spatially extended excited states to the spin density gives the correct order of magnitude for the isotropic interaction with the more distant neighbours. It will be shown that only a perturbation of the kind of the point ion potential gives the correct results. As stated recently, the angular dependent part of the cubic potential produced by the point ions proves to be one of the leading terms neglected in the free-ion approximation. The theoretical concepts known for the transition-metal ion complexes cannot be applied without substantial modifications and extensions to substitutional defects of these ions in salts.





Author: R. Bauer K. Differt

Source: https://hal.archives-ouvertes.fr/



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