A magnetic stack having a ferromagnetic free layer, a ferromagnetic pinned reference layer, a non-magnetic spacer layer between the free layer and the reference layer, and a variable layer proximate the free layer. The variable layer is antiferromagnetic at a first temperature and paramagnetic at a second temperature higher than the first temperature. During a writing process, the variable layer is paramagnetic. For magnetic memory cells, such as magnetic tunnel junction cells, the variable layer provides reduced switching currents.