Title: REPLICA ORNSTEIN-ZERNIKE EQUATIONS FOR POSITIONALLY FROZEN HEISENBERG SYSTEMS
Author(s): E.Lomba, C.Martin (Instituto de Qu'imica F'isica Rocasolano (CSIC), Serrano 119, E-28006 Madrid, Spain)

We present the formulation of the Replica Ornstein-Zernike equations for a model of positionally frozen disordered Heisenberg spin system. The results are obtained for various models, one in which the particle positions correspond to a frozen hard sphere fluid, another system in which the configurations are generated by a random insertion of hard spheres, a system of randomly distributed spins, and finally a system corresponding to a soft sphere fluid quenched at high and low temperatures. We will see that the orientational structure of the spin system is fairly well reproduced by the integral equation which, however, does not correctly account for the critical behaviour.

Key words: Heisenberg system, integral equations, ferromagnetic transition, spinglass
PACS: 75.50.Lk, 61.20.Ja, 64.60.Fr