VALENCE-ELECTRON STATES OF YBA2CU3O7-DELTA CHARACTERIZED BY COMBINED X-RAY AND PHOTOEMISSION-STUDIES

被引:19
作者
DRAGER, G [1 ]
WERFEL, F [1 ]
LEIRO, JA [1 ]
机构
[1] UNIV TURKU,DEPT PHYS SCI,SF-20500 TURKU 50,FINLAND
来源
PHYSICAL REVIEW B | 1990年 / 41卷 / 07期
关键词
D O I
10.1103/PhysRevB.41.4050
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
X-ray-emission (XES), x-ray-excited photoelectron (XPS), and ultraviolet-excited photoelectron spectra of YBa2Cu3O7- have been measured and arranged on a common binding-energy scale by XPS core lines. Three main valence-band (VB) structures at 2.7, 3.7, and 4.8 eV relative to the Fermi level (EF=0) could be identified representing hybridized Cu 3d/4pO 2p states. The VB XES and photoelectron spectra are strongly influenced by correlation and charge-transfer effects and hence reproduce the density of states (DOS) of excited multiple-hole states but not the one-hole ground-state DOS. These processes are responsible for the observed differences between high-energy spectroscopic results and one-electron theory. From the XES compared with calculations we estimate a local partial correlation shift of the theoretical Fermi level (EFs/rcorr) in the energy range 0.61.6 eV. Charge transfer and screening processes contribute to the x-ray transitions of the selective-type Cu 2pd10Ld9L and O 1sp6Cu 3d9d9L owing to Cu L and O K, respectively. With the mechanism of charge transfer and band shift acting in highly correlated electron systems, such as high-temperature superconducting compounds, a possible explanation for the unusually low DOS at EF in excitation spectra is given. © 1990 The American Physical Society.
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页码:4050 / 4055
页数:6
相关论文
共 34 条
[1]  
ANISIMOV VI, 1988, FIZ MET METALLOVED+, V65, P207
[2]  
ANISIMOV VI, 1988, FIZ MET METALLOVED+, V65, P204
[3]   X-RAY WAVELENGTHS [J].
BEARDEN, JA .
REVIEWS OF MODERN PHYSICS, 1967, 39 (01) :78-&
[4]   ELECTRONIC-STRUCTURE OF YBA2CU3O7-DELTA INCLUDING STRONG CORRELATION-EFFECTS [J].
COSTAQUINTANA, J ;
LOPEZAGUILAR, F ;
BALLE, S ;
SALVADOR, R .
PHYSICAL REVIEW B, 1989, 39 (13) :9675-9678
[5]   ELECTRON-MICROSCOPY AND MICROANALYSIS OF A YBA2CU3OX SUPERCONDUCTING OXIDE [J].
DOU, SX ;
BOURDILLON, AJ ;
SORRELL, CC ;
RINGER, SP ;
EASTERLING, KE ;
SAVVIDES, N ;
DUNLOP, JB ;
ROBERTS, RB .
APPLIED PHYSICS LETTERS, 1987, 51 (07) :535-537
[6]   THE CHANGES IN THE VALENCE BAND IN CU2O, CUO AND YBA2CU3O7-X DETERMINED BY THE X-RAY-EMISSION [J].
DRAHOKOUPIL, J ;
POLCIK, M ;
POLLERT, E .
SOLID STATE COMMUNICATIONS, 1988, 66 (04) :455-457
[7]  
FISHER DW, 1965, J APPL PHYS, V36, P2048
[8]  
FISHER DW, 1965, J CHEM PHYS, V42, P3814
[9]  
FUGGLE JC, 1988, INT J MOD PHYS B, V1, P1185
[10]   SPECTROSCOPIC EVIDENCE FOR STRONGLY CORRELATED ELECTRONIC STATES IN LA-SR-CU AND Y-BA-CU OXIDES [J].
FUJIMORI, A ;
TAKAYAMAMUROMACHI, E ;
UCHIDA, Y ;
OKAI, B .
PHYSICAL REVIEW B, 1987, 35 (16) :8814-8817