An Ising model is presented for a simple cubic-type structure, to determine the magnetic properties for superlattices of periodic Ak (ApB1-p)1Bh formula consisting of k layers of spin-1/2 A ions, h layers of spin-1/2 B ions and single layer disordered alloy interfaces between them. The interface layers are characterized by random arrangements of A and B ions so that (ApB1-p)1 is a two-dimensional thermodynamically stable alloy. The magnetic properties studied concern notably the phase diagrams and the sublattice magnetizations of these systems. The model is general and can be used for ferro- or anti-ferromagnetic A-B exchange couplings. In this paper the A-A and B-B exchange couplings are considered ferromagnetic with no loss of generality. An effective field theory is employed to calculate the properties of these systems. We apply the method to various Fek(Fep Tb1-p)1 Tbh superlattices. The needed exchange constants for the two-dimensional alloy interface are calculated in the framework of this model, and used to calculate these properties for different concentrations 0 ≤ p ≤ 1, for these superlattices. The architecture and concentration dependence of the magnetic properties is an important feature of this paper, allowing a useful experimental analysis of similar systems.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films