Effect of the resistance-area product on the temperature increase of nanopillar for spin torque magnetic memory

We investigated the increase in temperature of a nanopillar due to the current injection for the current-induced magnetization switching. Particular focus was made on the effect of the resistance-area (RA) product on the temperature increase of a nanopillar, which is an important parameter for applications in spin-transfer torque magnetic random access memory. With the hot electron model, the RA product and area dependence of the nanopillar temperature were obtained using a finite element method. The dependency of the increase in temperature on the current density, current directions, and pulse width were also examined. The nanopillar temperature was found to be proportional to the RA product, and decreased with decreasing cross-sectional area of the pillar. In contrast to expectations, an increase in nanopillar temperature was not serious over a wide range of parameters.