Substitution effects in Bi2Sr2(Ca1-xYx)Cu2O8+delta studied by X-ray absorption spectroscopy
Journal
Physica C
Journal Volume
341
Pages
383-386
Date Issued
2000
Author(s)
Abstract
The Bi2Sr2(Ca1-xYx)Cu2O 8+δ system over the homogeneity range x = 0 ∼ 1.0 has a maximal superconducting transition temperature (Tc) of around 92 K at x = 0.2. The hole distribution of overdoped, optimum doped and underdoped states in Bi2Sr2(Ca1-xYx)Cu2O 8+δhas been investigated by high-resolution O K-edge X-ray-absorption near-edge-structure (XANES) spectra. Near the O Is edge, a well-pronounced pre-edge peak with maximum at ∼528.3 eV is found, which is ascribed to the excitations of O Is electron to O 2p hole states located in the CuO2 planes. The intensity of this pre-edge peak decreases as the Y doping increases, demonstrating that the chemical substitution of Y3+ for Ca2+ in Bi2Sr2(Ca1-xYx)Cu2O 8+δ gives rise to a decrease in hole concentrations within the CuO2 planes. Moreover, the correlation between Tc and critical current density (Jc) as a function of doping concentration has been studied. It is important to point out that the highest Jc across the system is appeared at the overdoped side with x = 0 in Bi2Sr2(Ca1-xYx)Cu2O 8+δ. © 2000 Elsevier Science B.V All rights reserved.
SDGs
Type
journal article