Low Temperature Physics: 45, 1046 (2019); https://doi.org/10.1063/1.5121280
Fizika Nizkikh Temperatur: Volume 45, Number 9 (September 2019), p. 1223-1230    ( to contents , go back )

Magnetic and structural correlations in the warwickite Mn2OBO3

V. Gnezdilov1,2, Yu. Pashkevich3, V. Kurnosov1, O.V. Zhuravlev3, D. Wulferding2, P. Lemmens2, N.V. Kazak4, Yu.V. Knyazev4, and S.G. Ovchinnikov4,5

1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauki Ave., Kharkiv 61103, Ukraine
E-mail: gnezdilov@ilt.kharkov.ua

2Institute for Condensed Matter Physics, TU Braunschweig, Braunschweig D-38106, Germany

3O.O. Galkin Donetsk Institute for Physics and Engineering of the National Academy of Sciences of Ukraine 46 Nauki Ave., Kyiv 03680, Ukraine

4Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia

5School of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk 660041, Russia

Received April 16, 2019, published online July 26, 2019

Abstract

We report a Raman scattering study of single-crystalline homometallic oxyborate Mn2OBO3, a compound realizing a one-dimensional ribbon-structure. Phonon excitations as a function of temperature and light polarization are compared to lattice dynamical calculations, giving evidence for a strong coupling between lattice and magnetic degrees of freedom. Furthermore, a broader feature with a distinct structure emerges at low temperatures. Based on our theoretical analysis, we assign this signal to specific two-magnon scattering processes related to high energy flat-band magnon branches.

Key words: geometric frustration, two-magnon Raman scattering, oxyborate.

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