Using ground state computations, we study the transition from a spin glass to a ferromagnet in 3D spin glasses when changing the mean value of the spin-spin interaction. We find good evidence for replica symmetry breaking up until the critical value where ferromagnetic ordering sets in, and no ferromagnetic spin glass phase. This phase diagram is in conflict with the droplet/scaling and mean fi...

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from the experimental facts observed in Cu32xAlMnx and it includes coupling between configurational and magnetic degrees of freedom that are appropriate for reprodu...

0031-9007= We propose and investigate the properties of a digital ferromagnetic heterostructure consisting of a -doped layer of Mn in Si, using ab initio electronic-structure methods. We find that (i) ferromagnetic order of the Mn layer is energetically favorable relative to antiferromagnetic, and (ii) the heterostructure is a two-dimensional half-metallic system. The metallic behavior is contr...

The electron spin polarization (ESP) at surfaces of bulk and thin film ferromagnetic materials has been investigated using electron capture spectroscopy (ECS), which probes the ESP of the topmost surface layer. At surfaces of PtMnSb, Tb and Fe,,B,,, we find nonhero ESP due to long-ranged or short-ranged ferromagnetic order. The sign of the ESP at surfaces of the Heusler alloy PtMnSb is in agree...