Thermal expansion of CaFe$_2$As$_2$: effect of annealing and cobalt doping

ORAL

Abstract

Careful choice of Co concentration and annealing/quenching temperature in the Ca(Fe$_{1-x}$Co$_x$)$_2$As$_2$ series allows for tuning the ground state of the from orthorhombic-antiferromagnetic to superconducting to collapsed tetragonal [1].In this talk temperature-dependent, $c$-axis, thermal expansion measurements on several sets of Co-doped CaFe$_2$As$_2$ single crystals that were subjected to a variety of annealing conditions will be presented. These samples were chosen to cover all salient regions of the 3D $x - T_{anneal} - T$ phase diagram. The thermal expansion signatures of different types of phase transitions observed in these series will be discussed and comparison with the other measurements will be made.\\[4pt] [1] S. Ran, {\it et al.}, PRB {\bf 85}, 224528 (2012).

*This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under contract No. DE-AC02-07CH11358.

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Authors

  • Sergey Bud'ko

    • The Ames Laboratory, Iowa State University, Ames, USA
    • Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University
    • Ames Laboratory, US DOE, Iowa State University
    • Department of Physics, Iowa State University
    • Ames Laboratory, US DOE, and Dept. of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA

  • Sheng Ran

    • Ames Laboratory, US DOE, and Dept. of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA

  • Paul C. Canfield

    • Ames Laboratory, US DOE, and Dept. of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA