Effect of Fluorination on the Structure and Superconducting Properties of the Hg-1201 Phase

A. M. Abakumov; V. L. Aksenov; V. A. Alyoshin; E. V. Antipov; A. M. Balagurov; D. A. Mikhailova; S. N. Putilin; M. G. Rozova

doi:10.1103/PhysRevLett.80.385

Effect of Fluorination on the Structure and Superconducting Properties of the Hg-1201 Phase

A. M. Abakumov, V. L. Aksenov, V. A. Alyoshin, E. V. Antipov, A. M. Balagurov, D. A. Mikhailova, S. N. Putilin, M. G. Rozova

DOI 10.1103/PhysRevLett.80.385 · Physical Review Letters

T1

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Abstract

A fluorination of the reduced HgBa2CuO4+δ(Hg−1201) with Tc=61K resulted first in an increase in Tc up to 97 K and then in a decrease and even a suppression of superconductivity due to overdoping. Neutron powder refinements performed on fluorinated HgBa2CuO4Fδ showed twice the amount of extra fluorine in comparison with those for the oxygenated Hg−1201 phases with close Tc. This supports the ionic model of doping in Hg−1201: two holes per oxygen and one hole per fluorine. The apical distances in Hg−1201 depend on the number of dopant atoms rather than on their charge. The exchange of extra oxygen for a double amount of fluorine shortens the apical Cu−O distances, while the in-plane distances and Tc do not vary.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
HgBa2CuO4+δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	61	Pressure not reported	unknown
HgBa2CuO4Fδ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	97	Pressure not reported	onset
HgBa2CuO4Fδ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	96	Pressure not reported	onset
HgBa2CuO4Fδ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	90	Pressure not reported	onset
HgBa2CuO4Fδ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	88	Pressure not reported	onset
HgBa2CuO4Fδ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	78	Pressure not reported	onset
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown