  It is crucial that magnetic memory devices formed from magnetic
heterostructures possess sizable spin-orbit torque (SOT) efficiency and high
thermal stability to realize both efficient SOT control and robust storage of
such memory devices. However, most previous studies on various types of
magnetic heterostructures have focused on only their SOT efficiencies, whereas
the thermal stabilities therein have been largely ignored. In this work, we
study the temperature-dependent SOT and stability properties of two types of
W-based heterostructures, namely W/CoFeB/MgO (standard) and CoFeB/W/CoFeB/MgO
(field-free), from 25 ^{\circ}C (298 K) to 80 ^{\circ}C (353 K). Via
temperature-dependent SOT characterization, the SOT efficacies for both systems
are found to be invariant within the range of studied temperatures.
Temperature-dependent current-induced SOT switching measurements further show
that the critical switching current densities decrease with respect to the
ambient temperature; thermal stability factors ({\Delta}) are also found to
degrade as temperature increases for both standard and field-free systems. The
memristive SOT switching behaviors in both systems with various pulse-widths
and temperatures are also examined. Our results suggest that although the SOT
efficacy is robust against thermal effects, the reduction of {\Delta} at
elevated temperatures could be detrimental to standard memory as well as
neuromorphic (memristive) device applications.
