2014/04/15 by Haifeng Li · 1 citation
Physics and Astronomy · #cond-mat.str-el #cond-mat.other #msc:02.10.-v #msc:75.10.Hk #msc:75.30.-m
paper · pdf · doi:10.1038/npjcompumats.2016.32
published as npj Comput Mater 2, 16032 (2016) · 5 Pages, 4 Figures
arxiv created 2014/04/15 · arxiv updated 2020/01/08
Identifying the nature of a spin-flop (SFO) transition, first- or second-order (FO or SO), remains a major challenge in condensed-matter physics due to the technically undistinguishable effect of misalignment between applied-field direction and the relevant antiferromagnetic (AFM) easy axis. A classical SFO transition is believed to be of FO in character. Here a mean-field theoretical calculation endowed with AFM exchange interaction (J), easy axis anisotropy (γ), uniaxial single-ion exchange anisotropy (D), and Zeeman coupling to a magnetic field parallel to the easy axis unambiguously reveals that a SO SFO transition indeed exists by virtue of its relatively lower free energy. Their equilibrium phase conditions are found to be: D ≥ 0 (FO); -(1)/(2) γ< D < 0 (SO). Compared numerically to the associated AFM and spin-flip phases, the deduced SO SFO transition results from a negative single-ion anisotropy which is restricted to a certain range by the anisotropic exchange interaction