On the YBa2Cu3O7 band structure

A tight binding analysis is used to investigate the features of the YBa2Cu3O7 band structure, and predictions of the physical properties of the two structures proposed for the distribution of oxygen in this compound are made. The first structure, in which parallel 'sandwiches' are bound by Y planes, is well established for oxygen-poor compounds with weak critical temperatures, T(c). The second structure, in which square CuO2 planes are perpendicular to BaO or YO planes, is shown to be more favorable for three-dimensional high-T(c) superconductivity in a weak coupling limit. The present analysis assumes that oxygen appears in the form of the O(2-) ion.