Magnetization plateaus and phase diagrams of the extended Ising model on the Shastry-Sutherland lattice: effects of long-range interactions

Abstract

Magnetization plateaus and phase diagrams of the extended Ising model on the Shastry-Sutherland lattice with the first $(J_1)$, second $(J_2)$, third $(J_3)$ fourth $(J_4)$ and fifth $(J_5)$ nearest-neighbour spin couplings are studied by the classical Monte Carlo method. It is shown that switching on $J_4$ and $J_5$ interactions (in addition to usually considered $J_1, J_2$ and $J_3$ interactions) changes significantly the picture of magnetization processes found for $J_4=J_5=0$ and leads to stabilization of new macroscopic magnetic phases (plateaus) with fractional magnetization. In particular, it is found that combined effects of $J_4$ and $J_5$ interactions generate the following sequence of plateaus with the fractional magnetization: $m/m_s$=1/9, 1/6, 2/9, 1/3, 4/9, 1/2, 5/9 and 2/3. The results obtained are consistent with experimental measurements of magnetization curves in selected rare-earth tetraborides.