PHASE-DIAGRAMS OF A FERROMAGNETIC AMORPHOUS BILAYER SYSTEM

Using the effective-field theory, we study phase diagrams of a ferroma gnetic amorphous bilayer system, consisting of two monolayers (A and B ) with different spins (S-A = 1/2 and S-B = 1/2, 1) and different inte raction constants coupled together with an interlayer coupling. The ef fects of amorphization in the monolayer B and in the interlayer coupli ng are investigated. The influence of the crystal-field interaction D, in the case S-A = 1/2 and S-B = 1, is also studied. A number of inter esting phenomena are obtained such as the dependence of the tricritica l behavior on amorphization. Other phenomena have been given in a vari ety of phase diagrams. The temperature dependence of the total magneti zation is also examined. (C) 1998 Elsevier Science B.V. All rights res erved.