Regular Article

Magnetic phase diagram of the Ising model with the long-range RKKY interaction

Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovakia

^a e-mail: farky@saske.sk

Received: 27 March 2019
Received in final form: 17 May 2019
Published online: 26 August 2019

Abstract

The standard Metropolis algorithm and the parallel tempering method are used to examine magnetization processes in the Ising model with the long-range RKKY interaction on the Shastry-Sutherland lattice. It is shown that the Ising model with RKKY interaction exhibits, depending on the value of the Fermi wave vector k_F, the reach spectrum of magnetic solutions, which is manifested in the appearance of new magnetization plateaus on the magnetization curve. In particular, we have found the following set of individual magnetization plateaus with fractional magnetization m ∕ m_s = 1 ∕ 18, 1/9, 1/8, 1/5, 1/4, 1/3, 3/8, 5/12, 1/2, 3/5, 2/3, which for different values of k_F form various sequences of plateaus, changing from very complex, appearing near the point k_F = 2π ∕ 1.2, to very simple appearing away this point. Since the change of k_F can be induced by doping (the substitution of rare-earth ion by other magnetic ion that introduces the additional electrons to the conduction band) the model is able to predict the complete sequences of magnetization plateaus, which could appear in the tetraboride solid solutions.