Spin-Glass Irreversibility Temperature and Magnetic Stabilization in Ferromagnet/Spin-Glass Bilayers

The authors numerically studied the irreversibility temperature (T-irr) of a spin glass (SG) and how to use a SG to stabilize a ferromagnet. The rate of T-irr/SG-anisotropic-field increment can reach approximate to 121 K T-1. In ferromagnet/SG bilayers, exchange bias (EB) may be enhanced fivefold at 10 K with increasing interfacial coupling (J(IF)), whereas the EB blocking temperature (T-B(EB)) does not change. However, decreases in SG exchange coupling (J(SG)) can twofold enhance T-B(EB) with maintaining a table-like EB. On the contrary, small J(IF) and large J(SG) are both destructive to coercivity. Nevertheless, EB field and coercivity are switchable, opening an opportunity to design temperature-controlled write-to-read switches.