Influence of frustration on a d=3 diluted antiferromagnet: FexZn1-xF2

The influence of a frustrated bond on the magnetic properties of a d=3 uniaxial (Ising) bcc diluted antiferromagnet, with emphasis in the compound FexZn1-xF2, is investigated by a local mean-field numerical simulation. In particular we find that the initial drop of the saturation staggered magnetization (M(S)) with concentration follows a percolation-like phenomenon characterized by an exponent beta(p). For the frustrated samples, however, this regime is followed by a second one identified by a 'long tail' effect such that M(S) is zero only al the percolation threshold. Our numerical data also confirms a spin-glass phase near this threshold.