Abstract
We have studied the electronic structure of the layered semiconductor TlS by means of 203T1 and 205Tl NMR and band structure calculation. The crystal structure of this compound is built from the metal-chalcogen layers formed of linked Tl3S42- tetrahedra and Tl+ ions located between the layers. Our experiments show significant interlayer indirect exchange coupling of thallium nuclei. Since the distances between thallium ions essentially exceed the sum of their ionic radii, it is concluded that such coupling is realized due to the overlap of the Tl electron wavefunctions across the intervening S atom. The exchange interaction has been evaluated by means of the quantitative spectral analysis. The band structure calculation shows that the top of the valence band is composed of mixed Tl+ 6s6pz-S 3s3pz-Tl 3+ 6s6pz states, yielding overlap of the T1 +-S-Tl3+ type. Such electronic structure gives rise to the effective interlayer coupling of Tl nuclear spins observed in the experiment. This effect is discussed along with the recently obtained NMR results in the chain thallium sulfide and selenide.
Original language | English |
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Pages (from-to) | 3071-3080 |
Number of pages | 10 |
Journal | Journal of Physics Condensed Matter |
Volume | 16 |
Issue number | 18 |
DOIs | |
State | Published - 12 May 2004 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics