Soft x-ray absorption spectroscopy studies of (110) YBa[sub 2]Cu[sub 3]O[sub 6.9] thin film.

Unoccupied states of the (110) YBa[sub 2]Cu[sub 3]O[sub 6.9] (YBCO) thin films were investigated by the Eab and Ec polarized O 1 s x-ray absorption near edge structure (XANES) spectroscopy. With correction of the self-absorption effect, the Eab O 1 s XANES spectra of the (110) YBCO films obtained from the normal incidence geometry and grazing incidence geometry are very similar. After the self-absorption correction, the Ec spectrum of the (110) YBCO film obtained from the normal incidence geometry is almost identical to that of the (001) YBCO film obtained from the grazing incidence geometry. Hole distribution over the different oxygen sites has been derived. The hole number in the apical sites in some thin films obtained in the present investigation is larger than that from the previous x-ray absorption studies of single crystals and from the theoretical calculations. The comparison of the XANES spectra between the (001) and (110) YBCO thin films is also presented. [ABSTRACT FROM AUTHOR]