A diluted mixed spin-2 and spin-5/2 ferrimagnetic Ising system; a study of a molecular-based magnet

Abstract

The magnetic properties of a diluted spin-2 and spin-5/2 ferrimagnetic Ising system are investigated on the basis of the effective-field theory with correlations. In particular, the effect of a positive single-ion anisotropy D on the compensation temperature in a pure system with D only on spin-5/2 atoms is investigated, in order to clarify the characteristic feature of the temperature dependence of the total magnetization M observed in a molecular-based magnetic material, . The influences of D and the concentrations of magnetic atoms on the properties of the system on a honeycomb lattice are examined. The results show that several (two or three) compensation points are possible in the diluted system with special values of D and concentrations of magnetic atoms.

The study of the phase diagram and internal energy of the mixed spin‐3/2 and spin‐5/2 ferrimagnetic Ising system with interlayer coupling by effective‐field theory; a simple approach of calculating internal energy

“…For a given 2 J , if the compensation point exists, it can only occur when D becomes larger than a critical value C D , which decreases with the increase of 2 J . These results are consistent with some previous studies about the mixed spin-2 and spin-5/2 [11,13,15] and the mixed spin-1 and spin-2 systems [18]. From detailed studies, we find that the compensation points can only appear when J 2 /|J 1 | > 0.91.…”

“…Many theoretical investigations dealing with two high-spin Ising models studied the system with an integer spin sublattice and a half-integer spin sublattice [9][10][11][12][13][14][15][16].…”

“…It is worth noting that there are a few works dealing with the layered mixed spin-2 and spin-5/2 Ising system on the honeycomb lattice [11][12][13][14][15][16] since the system is related to a molecular-based magnet AFe II Fe III (C 2 O 4 ) 3 (A = N(n-C 3 H 7 ) 4 ) [17], and particularly interesting is the fact that the magnetic transition-metallic ions in the magnets can be replaced by other metal ions if the valencies of the ions are not changed. Thus, theoretically, molecular-based magnetic materials containing two integer spin sublattices or two half-integer spin sublattices with similar crystal structures can be synthesized if the experimental ingredients are changed.…”

Magnetic Properties and Size Effects of Spin-1/2 and Spin-1 Models of Core-Surface Nanoparticles in Different Type Lattices

“…These are of interest because they have less translational symmetry than their single-spin counterparts since they consist of two interpenetrating inequivalent sublattices. The latter property is very important to study a certain type of ferrimagnetism, namely molecular-based magnetic materials which are of current interest (Kaneyoshi et al, 1998).…”

“…Ising models (Erdem, 1995;Keskin, & Erdem 1997;Erdem & Keskin, 2001;Erdem, 2009;Erdem, 2008;Chen & Levy, 1973) and thier variants such as Blume-Capel (Blume, 1966;Capel, 1966;Bakchich, et al, 1994), Blume-Emery-Griffiths (Blume, et al, 1971;Achiam, 1985;Hoston, & Berker, 1991;Bakkali, 1996;Goveas & Mukhopadhyay, 1997;Keskin, et al, 1999;Temizer, 2008) and mixed spin (Benayad & Dakhama 1997;Kaneyoshi, 1998;Albayrak, & Yigit, 2005;Albayrak, & Yigit, 2006;) models were regarded as theoretical simplifications, designed to model the essential aspects of cooperative system (Kikuchi,1951) without detailed correspondence to specific materials.…”