Document Type

Article

Publication Date

6-25-2014

Journal or Book Title

Physical Review B

Volume

89

First Page

220509(R)

DOI

10.1103/PhysRevB.89.220509

Abstract

ARTICLE TEXT
SUPPLEMENTAL MATERIAL
REFERENCES

ABSTRACT

We report measurements of electrical resistivity under pressure to 5.8 GPa, magnetization to 6.7 GPa, and ac susceptibility to 7.1 GPa in KFe2As2. The previously reported change of slope in the pressure dependence of the superconducting transition temperature Tc(p) at a pressure p∗∼1.8 GPa is confirmed, and Tc(p) is found to be nearly constant above p∗ up to 7.1 GPa. The T−p phase diagram is very sensitive to the pressure conditions as a consequence of the anisotropic uniaxial pressure dependence of Tc. Across p∗, a change in the behavior of the upper critical field is revealed through a scaling analysis of the slope of Hc2 with the effective mass as determined from the Acoefficient of the T2 term of the temperature-dependent resistivity. We show that this scaling provides a quantitative test for the changes of the superconducting gap structure and suggests the development of a kz modulation of the superconducting gap above p∗ as a most likely explanation.

Comments

This article is from Physical Review B 89 (2014): 220509(R), doi:10.1103/PhysRevB.89.220509. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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