The O-1s x-ray near-edge-absorption spectra of La1.5-xCaxBa1.5Cu3Oy have been measured by using synchrotron radiation. Their spectral features of the pre-edge spectra indicate that there is an electronic structure change similar to the effect of Pr in Y1-xPrxBa2Cu3O7-δ; the holes on the CuO2 planes increase with the doping concentration of Ca ions; not all the excess oxygen (for y≧7.0) in the basal plane supply holes; and there is a sign of increasing, rather than decreasing, the holes around the apical oxygen O(4) with the increase of the replacement of Ba by La on the Ba sites, an indication of a redistribution of holes.
|頁（從 - 到）||4357-4362|
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||已發佈 - 1999|
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