Charge state of copper ions in the YBa2Cu3O6.8 single crystal (1.5 at % Ce): X-ray photoelectron and absorption studies

• Published in: Physics of metals and metallography Vol. 111; no. 4; pp. 361 - 366
• Main Authors: Blinova, Yu. V., Galakhov, V. R., Kuznetsov, M. V., Sudareva, S. V., Semenova, A. S., Shkvarin, A. S.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-04-2011
• Subjects: ABSORPTION; Annealing; ANNEALING PROCESSES; Argon; Charge; Chemistry and Materials Science; Copper; COPPER OXIDE; Covalence; Diffusion; Materials Science; Metallic Materials; Phase Transformations; Photoelectrons; Single crystals; Structure; SUPERCONDUCTORS; X RAYS; YTTRIUM OXIDE; HTSC; single crystal; phase transformation; X-ray photoelectron and absorption spectroscopy
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X1103001X

X-ray photoelectron and absorption spectra of YBa
2
Cu
3
O
6.8
single crystals (1.5 at % Ce) annealed in vacuum, in argon, and in air have been studied. It has been established that the heat treatment in air at 200°C for 100 h led to the appearance of Cu
1+
ions in a subsurface layer and to an increase in the degree of covalence of the Cu-O bonds in the “bulk” of the sample.