Superconductivity in Y0.6Pr0.4Ba2−xSrxCu3O7−δ: The role of apical oxygen in hybridization

Xiaolong Chen; Jingkui Liang; Yong Wang; Fei Wu; Guanghui Rao

doi:10.1103/PhysRevB.51.16444

← Back to search

Superconductivity in Y0.6Pr0.4Ba2−xSrxCu3O7−δ: The role of apical oxygen in hybridization

Xiaolong Chen, Jingkui Liang, Yong Wang, Fei Wu, Guanghui Rao

DOI 10.1103/PhysRevB.51.16444 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

The structural and electric properties of Y0.6Pr0.4Ba2−xSrxCu3O7−δ have been investigated as a function of x. X-ray powder-diffraction patterns indicate that a solid solution forms with x extending to about 1.4. It is found that the substitution of Sr for Ba results in a contraction in the c axis at the same rate as in YBa2−xSrxCu3O7−δ. The oxygen content and Tc are found to remain essentially unchanged with increasing Sr. Our analysis suggests that the contraction in c arises mainly from the shift of the apical oxygen and from a shift of Ba(Sr) towards the CuO2 planes. The apparent shift of the apical oxygen does not seem to influence the hybridization between the Pr 4f electrons and the valence band of the CuO2 planes significantly. The hybridization is more sensitive to the bond length between the Pr and the oxygen located in the CuO2 planes. Tc in this system appears to be controlled both by the shift of the apical oxygen and by the hybridization.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
Y0.6Pr0.4Ba2-xSrxCu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	44	Pressure not reported	midpoint
Y0.6Pr0.4Ba2-xSrxCu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	44	Pressure not reported	midpoint
YBa2-xSrxCu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
Y1-xPrxBa2Cu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown