X-Ray Photoelectron Spectra of La1+xBa2-xCu3Oy (x=0.2, 0.3, 0.4, 0.5)
The X-ray photoelectron spectra were measured on the single phase La1+x Ba2-x Cu30y (x=0.2, 0.3,0.4, 0.5).
Oxygen content y was be increased by the increase of La content x. The critical temperature Tc was decreased by the increase of La content x. The binding energy of Cu 2ρ states was closely related with Tc. Superconductivity seemed to occur below the critical value of the Cu binding energy of about 934.25eV. Below the critical value of the Cu binding energy, Tc could be increased by decreasing the binding energy of Cu.
Remarkable differences in 0 Is and Ba 3d states were observed between the superconductor and non-superconductor. The spectrum of the non-superconductor was similar to that of La2O2 indicating strong La-0 bond. In the superconductor the full width of half maximum intensity of Ba 3d 5/2 was lower than that of the non-superconductor.
These results might suggest that the free holes around Cu-0 bonds contribute to the superconductivity.
KeywordsBinding Energy Free Hole Half Maximum Intensity Heat Treated Powder Oxygen Content Analysis
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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