  We investigate the nature of the critical behaviour of the random-anisotropy
Heisenberg model (RAM), which describes a magnetic system with random uniaxial
single-site anisotropy, such as some amorphous alloys of rare earths and
transition metals. In particular, we consider the strong-anisotropy limit
(SRAM), in which the Hamiltonian can be rewritten as the one of an Ising
spin-glass model with correlated bond disorder: H = - J \sum_{< xy >} j_{xy}
\sigma_x \sigma_y, where j_{xy} = \vec{u}_x \cdot \vec{u}_y and \vec{u}_x is a
random three-component unit vector. We performed Monte Carlo simulations of the
SRAM on simple cubic L^3 lattices, up to L=30, measuring correlation functions
of the replica-replica overlap, which is the order parameter at a glass
transition. The corresponding results show critical behaviour and finite-size
scaling. They provide evidence of a finite-temperature continuous transition
with critical exponents \eta_o=-0.24(4) and \nu_o=2.4(6). These results are
close to the corresponding estimates that have been obtained in the usual Ising
spin-glass model with uncorrelated bond disorder, suggesting that the two
models belong to the same universality class. This is consistent with arguments
that suggest that the disorder correlations present in the SRAM are irrelevant.
