Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

6-1-2012

Journal or Book Title

Physical Review B

Volume

85

Issue

22

First Page

224528

DOI

10.1103/PhysRevB.85.224528

Abstract

We have grown single-crystal samples of Co substituted CaFe2As2 using an FeAs flux and systematically studied the effects of annealing/quenching temperature on the physical properties of these samples. Whereas the as-grown samples (quenched from 960 degrees C) all enter the collapsed tetragonal phase upon cooling, annealing/quenching temperatures between 350 and 800 degrees C can be used to tune the system to low-temperature antiferromagnetic/orthorhomic or superconducting states as well. The progression of the transition temperature versus annealing/quenching temperature (T-T-anneal) phase diagrams with increasing Co concentration shows that, by substituting Co, the antiferromagnetic/orthorhombic and the collapsed tetragonal phase lines are separated and bulk superconductivity is revealed. We established a 3D phase diagram with Co concentration and annealing/quenching temperature as two independent control parameters. At ambient pressure, for modest x and T-anneal values, the Ca(Fe1-xCox)(2)As-2 system offers ready access to the salient low-temperature states associated with Fe-based superconductors: antiferromagnetic/orthorhombic, superconducting, and nonmagnetic/collapsed tetragonal.

Comments

This article is published as Ran, Sheng, Serguei L. Bud'ko, Warren E. Straszheim, J. Soh, Min Gyu Kim, Andreas Kreyssig, Alan I. Goldman, and Paul C. Canfield. "Control of magnetic, nonmagnetic, and superconducting states in annealed Ca (Fe 1− x Co x) 2 As 2." Physical Review B 85, no. 22 (2012): 224528. DOI: 10.1103/PhysRevB.85.224528. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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