Electronic structure and magnetic interactions of the spin-chain compounds Ca2CuO3 and Sr2CuO3
Data(s) |
25/01/2010
25/01/2010
2000
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Resumo |
The results are presented of a combined periodic and cluster model approach to the electronic structure and magnetic interactions in the spin-chain compounds Ca2CuO3 and Sr2CuO3. An extended t-J model is presented that includes in-chain and interchain hopping and magnetic interaction processes with parameters extracted from ab initio calculations. For both compounds, the in-chain magnetic interaction is found to be around -240 meV, larger than in any of the other cuprates reported in the literature. The interchain magnetic coupling is found to be weakly antiferromagnetic, -1 meV. The effective in-chain hopping parameters are estimated to be ~650 meV for both compounds, whereas the value of the interchain hopping parameter is 30 meV for Sr2CuO3 and 40 meV for Ca2CuO3, in line with the larger interchain distance in the former compound. These effective parameters are shown to be consistent with expressions recently suggested for the Néel temperature and the magnetic moments, and with relations that emerge from the t-J model Hamiltonian. Next, we investigate the physical nature of the band gap. Periodic calculations indicate that an interpretation in terms of a charge-transfer insulator is the most appropriate one, in contrast to the suggestion of a covalent correlated insulator recently reported in the literature. |
Formato |
13 p. application/pdf |
Identificador |
0163-1829 http://hdl.handle.net/2445/10852 169854 |
Idioma(s) |
eng |
Publicador |
The American Physical Society |
Relação |
Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevB.63.014404 Physical Review B, 2000, vol. 63, núm. 1, p. 014404-1-014404-13 |
Direitos |
(c) The American Physical Society, 2000 info:eu-repo/semantics/openAccess |
Palavras-Chave | #Estructura electrònica #Interaccions electromagnètiques #Superconductivitat #Propietats magnètiques #Electronic structure #Electromagnetic interactions #Magnetic properties #Superconductivity |
Tipo |
info:eu-repo/semantics/article |