  We study the glass formation in two- and three-dimensional Ising and
Heisenberg spin systems subject to competing interactions and uniaxial
anisotropy with a mean-field approach. In three dimensions, for sufficiently
strong anisotropy the systems always modulates in a striped phase. Below a
critical strength of the anisotropy, a glassy phase exists in a finite range of
temperature, and it becomes more stable as the system becomes more isotropic.
In two dimension the criticality is always avoided and the glassy phase always
exists.
