Lattice dynamics of antiperovskite manganese nitrides exhibiting large negative and positive thermal expansion

ORAL

Abstract

Antiperovskite manganese nitrides Mn3AN (where A is a metal or semiconducting element) have strong charge-spin-lattice interactions resulting in magnetovolume effects such as large positive (PTE) and negative thermal expansion (NTE) over transitions between their ferrimagnetic, antiferromagnetic, and paramagnetic phases [1]. We grow films of Mn3Cu1-xGexN with x = 0.1 to 0.5, which exhibit tunable NTE coefficients over a 50 K region, occurring anywhere from around 100 K to around 400 K depending on x. We also grow films of Mn3Cu1-xNixN with x = 0.09 to 0.10, which have a first order hysteretic PTE of 1-1.5% near 100 K and exhibit NTE for a total lattice contraction of roughly 0.5% over a 25 K range around 175 K. These regions are linked to transitions in magnetic phases. To probe the coupling of the structure and magnetism, we have measured the X-ray diffraction following photoexcitation within and through the interesting regions at the Advanced Photon Source. We present the complex lattice dynamics and discuss the spin-lattice coupling driving their response.

[1] Takenaka, K., et al. Appl. Phys. Lett. 87, 261902 (2005).

*Work at UCSD was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contracts No. DE-SC0018237 and DE-SC0001805.

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Presenters

  • Sheena Patel

    • University of California, San Diego
    • Physics, University of California San Diego

Authors

  • Sheena Patel

    • University of California, San Diego
    • Physics, University of California San Diego

  • Stjepan B Hrkac

    • University of California, San Diego

  • Jeffrey Brock

    • University of California, San Diego
    • Center for Memory and Recording Research, University of California, San Diego

  • Nelson Hua

    • University of California, San Diego

  • Haidan Wen

    • Argonne National Laboratory
    • Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
    • Advanced Photon Source, Argonne National Laboratory

  • Oleg Shpyrko

    • University of California, San Diego

  • Eric Fullerton

    • University of California, San Diego
    • Center for Magnetic Recording Research, University of California at San Diego
    • Center for Memory and Recording Research, University of California, San Diego
    • CMRR, University of California San Diego
    • Center for Memory and Recording research, UCSD