Magnetic interplay of Mn and Yb sites in YbMn2Si2 – Crystal field splitting

Authors

Richard A. Mole, ANSTO, University Of New South Wales
David L. Cortie, University of WollongongFollow
Michael Hofmann
Jian Li Wang, University of WollongongFollow
Wayne D. Hutchison, University Of New South Wales
Dehong Yu, Australian Nuclear Science And Technology Organisation
Xiaolin Wang, University of WollongongFollow
Stewart J. Campbell, University Of New South WalesFollow

RIS ID

144148

Publication Details

Mole, R., Cortie, D., Hofmann, M., Wang, J., Hutchison, W., Yu, D., Wang, X. & Campbell, S. (2020). Magnetic interplay of Mn and Yb sites in YbMn2Si2 – Crystal field splitting. Journal of Alloys and Compounds, 845

Abstract

© 2020 The crystal field splitting of YbMn2Si2 has been investigated over the temperature range 5–65 K using inelastic neutron scattering at a wavelength of 2.345 Å (resolution 800 μeV; dynamic range ∼10 meV). The excitation spectra have been analysed using a crystal field model above and below TN2, the temperature at which the collinear antiferromagnetic structure AFil transforms to the low-temperature structure in which the magnetic cell is doubled along the c-axis (TN1 = 526(4) K > T > TN2 = 32(2) K). The calculated excitation spectra show good agreement with the observed spectra for the unique environment of Yb3+ ions in the collinear antiferromagnetic structure AFil above TN2 and for the inequivalent sites of Yb3+ ions below TN2. This agreement has been obtained with a model for the low-temperature region in which a molecular field with optimal components in the x, y and z directions of Bx = 13.5 T, By = 65 T, Bz = 21.3 T is included. The pronounced components in the x and y directions are discussed in relation to the significant contraction of ∼0.1% of the c lattice parameter below the TN2 magnetic transition.