"Ridge" Fermi Surface Study in Metallic (R)Ba2Cu3O7-δ (R = Y, Dy) and in Oxygen Deficient YBa2Cu3O7-δ by Positron Annihilation |
| L. Hoffmann, Α.A. Manuel, B. Barbiellini, Μ. Peter, A. Shukla and E. Walker Département de Physique de la Matière Condensée, Université de Genéve, 24 Quai E. Ansermet, 1211 Genève 4, Switzerland |
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| We present a detailed positron 2D-ACAR measurements study of the "ridge" Fermi surface of (R)Ba2Cu3O7-δ (R = Y, Dy) compared to full-potential linearized augmented plane wave and linear muffin-tin orbital calculations. From different 2D-ACAR projections measured in DyBa2Cu3O7-δ, a 3D model of the momentum density of the ridge was established and is in good agreement with LMTO calculations of YΒa2Cu3O7, confirming the description of the ridge Fermi surface by local density approximation calculations. The ridge is also studied in oxygen deficient YΒa2Cu3O7-δ. With growing δ, the ridge disappears without changing in width. This is consistent with full-potential linearized augmented plane wave calculations of YΒa2Cu3O6.5, and supports the phase separation model of Mesot et al. |
| DOI: 10.12693/APhysPolA.88.147 PACS numbers: 71.25.Ηc, 74.72.Βk, 74.72.Jt, 78.70.Bj |