First-order antiferromagnetic transitions in CaMn<sub>2</sub>P<sub>2 </sub>and SrMn<sub>2</sub>P<sub>2</sub> single crystals containing corrugated-honeycomb Mn sublattices

ORAL

Abstract

CaMn2P2 and SrMn2P2 are insulators that crystallize in the trigonal CaAl2Si2-type structure containing corrugated honeycomb layers of Mn2+ spins 5/2. Magnetic susceptibility χ and heat capacity measurements versus temperature T reveal a strong first-order antiferromagnetic (AFM) transition in CaMn2P2 at TN = 69.8(3) K and a weak first-order AFM transition in SrMn2P2 at TN = 53(1)  K. The χ(T) data for both compounds exhibit nearly isotropic and T-independent behavior below TN. NMR measurements indicate a commensurate AFM structure for CaMn2P2 and an incommensurate one for SrMn2P2. CaMn2P2 and SrMn2P2 are rare examples where an AFM transition in zero-magnetic field is thermodynamically of first order. These first-order AFM transitions are unique among the (Ca, Sr, Ba)Mn2(P, As, Sb, Bi)2 compounds that exhibit second-order AFM transitions. Determining the mechanism for the first-order transitions may lead to the development of new materials of technological interest.

*Work was supported by the USDOE under Contract No. DE-AC02-07CH11358. The research of L.C. and B.B.I. was supported by the Villum Foundation.

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Publication: N. S. Sangeetha et al., https://arxiv.org/abs/2105.02394 (2021)

Presenters

  • N. S. Sangeetha

    • Ames Laboratory, Iowa State University, Ames, Iowa 50011
    • Institute for Experimental Physics IV, Ruhr University Bochum, 44801 Bochum, Germany
    • Ruhr Univ Bochum

Authors

  • N. S. Sangeetha

    • Ames Laboratory, Iowa State University, Ames, Iowa 50011
    • Institute for Experimental Physics IV, Ruhr University Bochum, 44801 Bochum, Germany
    • Ruhr Univ Bochum

  • S. Pakhira

    • Ames Laboratory
    • Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • Q.-P. Ding

    • Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • L. Krause

    • Aarhus University, DK-8000 Aarhus C, Denmark

  • H. Lee

    • Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • V. Smetana

    • Stockholm University
    • Department of Materials and Environmental Chemistry, Stockholm University, Sweden
    • Stockholm University, Svante Arrhenius väg 16 C, 106 91 Stockholm, Sweden

  • A. Mudring

    • Aarhus University, DK-8000 Aarhus C, Denmark; Stockholm University, Svante Arrhenius väg 16 C, 106 91 Stockholm, Sweden

  • B. Brummerstedt Iversen

    • Aarhus University, DK-8000 Aarhus C, Denmark

  • Y. Furukawa

    • Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • D.C. Johnston

    • Ames Laboratory, USA
    • Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA