Micromagnetic simulation of critical current density of spin transfer torque switching in a full-Heusler Co2FeAl0.5Si0.5 alloy spin valve nanopillar

► We investigate critical current density of switching through micromagnetic simulation. ► Different currents and fields give rise to a shift of hysteretic loop. ► Three critical current densities have different slopes with α and η. ► The area of resistance-current hysteretic loop decreases as the size decreases. ► Magnetization reversals have different switching processes between different sizes.