VARIATION OF LA 3D PHOTOELECTRON-SPECTRA OF LA1.9SR1.1-XCAXCU2O6+DELTA

X-ray photoelectron spectra for La 3d core-level region were measured to discuss the effect of cation substitution on electronic state of a cation substituted system of La1.9Sr1.1-xCaxCu2O6+delta. Content of ox ygen decreased with the increase of Ca content, x. Relative intensity ratio for the main (\3d(9)4f(0)>) peak (I-M) to satellite (\3d(9)4f(1) (L) under bar>) peak (I-S) in La 3d region decreased with the increas e of Ca content, even though the averaged interatomic distance between La and oxide ion was kept almost constant. It was found that the vari ation of I-M/I-S ratio corresponded to variation of oxygen content, de lta. It was concluded that the variation of I-M/I-S with Ca content wa s due to the change in hole concentration in oxygen site. (C) 1998 Els evier Science B.V.