Magneto-elastic coupling in molecule-based materials: [Ru$_2$(O$_2$CMe)$_4$]$_3$[Cr(CN)$_6$] and Mn[N(CN)$_2$]$_2$

ORAL

Abstract

We measured the infrared vibrational response of two prototypical molecule-based magnets, [Ru$_2$(O$_2$CMe)$_4$]$_3$[Cr(CN)$_6$] and Mn[N(CN)$_2$]$_2$. We find that both temperature and magnetic field driven transitions impact spin-lattice interactions in these materials. For instance, through the N\'eel transition, Cr--CN stretching and bending modes as well as Ru-O stretching mode in [Ru$_2$(O$_2$CMe)$_4$]$_3$[Cr(CN)$_6$] display sudden frequency shifts and a strong hysteresis that reveal local structure changes around Cr and Ru centers in response to magnetic ordering. On the other hand, the dicyanamide ligands in Mn[N(CN)$_2$]$_2$ display pronounced sensitivity to the 30 T magnetic quantum critical transition, in line with our calculations that point toward the importance of N--C--N and C--N--C angles for the mediation of Mn$\cdots$Mn spin exchange interactions.

*This work is supported by the U.S. Department of Energy.

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Authors

  • T.V. Brinzari

    • University of Tennessee

  • Q.-C. Sun

    • University of Tennessee

  • J.L. Musfeldt

    • University of Tennessee

  • Li-Chun Tung

    • National High Magnetic Field Laboratory

  • Y.J. Wang

    • National High Magnetic Field Laboratory

  • Jia Liu

    • North Carolina State University
    • NCSU

  • M.-H. Whangbo

    • North Carolina State University

  • J.S. Miller

    • University of Utah

  • Jamie Manson

    • Eastern Washington University
    • Dept. of Chem. and Biochem., E. Washington Univ., Cheney, WA 99004, USA

  • John Schlueter

    • Argonne National Laboratory