Monte Carlo investigation of transition and compensation temperatures of Fe/Tb multilayers

A Monte Carlo investigation of the A thickness (A equivalent to Fe) depende nce of the transition and compensation temperatures of a simple cubic Heise nberg A/B bilayer is carried out. Our model, which includes a few mixed pla nes of the A(1-x)B(x) type that represent the disordered interfaces, basica lly consists of several coupled magnetic parts with different bulk transiti on temperatures. Numerical results are compared with the experimental data for amorphous Fe/Tb multilayers. The simulated Fe thickness (t(Fe)) depende nce of T-C, which reproduces the decrease of T-C as t(Fe) increases, is con sistent with the experimental one. Since our simulations indicate that the magnetic ordering is driven by the disordered interfaces, the decrease of T -C is explained by the fact that the interfaces are more and more decoupled as t(Fe) increases. The experimental thermal behavior of each sublattice m agnetization can be reproduced with a Tb-magnetic moment of 6 mu(B) which s eems to be reasonable for amorphous layers, whereas a value of 9 mu(B) is t oo large. Accordingly, a compensation point has been observed for a Fe thic kness range that agrees with the experimental one. The simulated and experi mental Fe thickness variations of T-comp are in reasonable agreement. (C) 2 000 American Institute of Physics. [S0021-8979(00)02601-3].