Chemical Pressure Effect and Dimer Formation in (Ba,Sr)Ni$_2$As$_2$ Solid Solutions

ORAL

Abstract

Although both BaNi$_2$As$_2$ and SrNi$_2$As$_2$ form in ThCr$_2$Si$_2$ structure, these materials display very different behaviors, owing in part to an important structural difference: while the Sr compound exhibits As-As bonds between layers, the Ba compound lacks these interlayer bonds. Thus, substitution of Sr into BaNi$_2$As$_2$ produces a positive chemical pressure effect on the system that pulls the NiAs layers closer together and towards As-As dimer formation. We will present the resulting phase diagram as determined by x-ray, chemical composition, electrical resistivity and magnetization measurements.

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Authors

  • Tyler Drye

    Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland-College Park, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742

  • Shanta R. Saha

    Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland-College Park, Ceter for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742

  • Johnpierre Paglione

    Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland-College Park, Ceter for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, University of Maryland, Department of Physics, University of Maryland, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, Center for Nanophysics and Advanced Materials, Dept. of Physics, University of Maryland, College Park