Electronic characteristics of Tl2Ba2CuO6: Fermi surface, positron wavefunction, electric field gradients, and transport parameters
✍ Scribed by David J. Singh; Warren E. Pickett
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 810 KB
- Volume
- 203
- Category
- Article
- ISSN
- 0921-4534
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✦ Synopsis
A number of properties identifiable from the electronic bands and one-electron wavefunctions have been obtained from a well converged self-consistent calculation of the electronic structure of T12Ba2CuO6. The Fermi surface is found to consist of two sheets: a two-dimensional barrel surface arising from the CuO2 layer, and a three-dimensional spheroid arising from states with strong T1-O character but actually extending throughout all layers of the structure. This feature has important implications for the transport properties, and especially for the degree ofanisotropy. We compare with transport data on single crystals of T12Ba2CuOe. The calculated Fermi surface of the spheroid is found to be in substantial agreement with the measured period of magnetization oscillations in the de Haas-van Alphen effect by Kido et al. The positron wavefunction engulfs the CuO2 layers, making this material a promising case for mapping out with positron 2D-ACAR the layer-derived Fermi surface that is believed to be central to high-temperature superconductivity. The electric field gradients are predicted and compared with calculations for other cuprates. The Hall coefficient R,~z (carrier motion on the a-b plane) is found to be positive and within a factor of 1.5 of that measured on ceramic samples, while the other non-vanishing component of the Hall tensor is predicted to be negative.