RENORMALIZATION-GROUP CALCULATION OF THERMODYNAMIC FUNCTIONS IN DISORDERED ISING SYSTEMS

We investigate the behaviour of the specific heat and the spontaneous magnetisation in bond disordered Ising ferromagnetic systems. We use a real space renormalisation group approach which allows the probabilit y distributions to evolve along the renormalisation process. Such stat istical treatment provides a natural description of various kinds of m agnetic disorder and gives a good approximation for d-dimensional syst ems. Our method is conceived to deal with different exchange coupling magnitudes, and therefore is suitable to deal with amorphous and dilut e disordered magnets.