Magnetic transitions and the magnetocaloric effect in the Pr1−xYxMn2Ge2 system

Authors

  • J. L. Wang,

    1. School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra, ACT, Australia
    2. Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW, Australia
    3. Bragg Institute, Australian Nuclear Science and Technology, Lucas Heights, NSW, Australia
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  • S. J. Campbell,

    Corresponding author
    1. School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra, ACT, Australia
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  • M. F. Md Din,

    1. Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW, Australia
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  • S. J. Kennedy,

    1. Bragg Institute, Australian Nuclear Science and Technology, Lucas Heights, NSW, Australia
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  • M. Hofmann

    1. Forschungs-Neutronequelle Heinz Maier-Leibnitz (FRM-II), Technische Universität München, Garching, Germany
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Abstract

Layered rare earth compounds in the RMn2X2 series (R = rare-earth; X = Ge, Si) are of interest for potential cooling applications at lower temperatures as they enable the structural and magnetic behavior to be controlled via substitution of R, Mn, and X atoms on the 2a, 4d, and 4e sites respectively. We continue investigations of the Pr1−xYxMn2Ge2 magnetic phase diagram as functions of both composition and Mn–Mn spacing using X-ray and neutron diffraction, magnetization and differential scanning calorimetry measurements. Pr1−xYxMn2Ge2 exhibits an extended region of re-entrant ferromagnetism around x ∼ 0.5 with re-entrant ferromagnetism at math formula for Pr0.5Y0.5Mn2Ge2. The entropy values −ΔSM around the ferromagnetic transition temperatures math formula from the layered antiferromagnetic AFl structure to the canted ferromagnetic structure Fmc (typically math formula) have been derived for Pr1−xYxMn2Ge2 with x = 0.0, 0.2, and 0.5 for ΔB = 0–5 T. The changes in magnetic states due to Y substitution for Pr are discussed in terms of chemical pressure, external pressure, and electronic effects.

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