Fig. 4: Field-free current-induced switching of magnetization with perpendicular components.
The schematic diagram of the set-up for SOT switching of perpendicular magnetization is shown in a, with small θM and b, with large θM. The yellow arrows indicate the ferromagnetic magnetization. The black arrows indicate the Ipulse. The results of field-free SOT switching with Ipulse (pulse width of 2 ms) applied along [\(\bar{1}10\)] and [001] are shown in c, for Pt(5)/Co(1.2)/NiO(20)/MgO heterostructure with θM = 16° and d, for Pt(5)/Co(0.6)/Pt(1.4)/NiO(20)/MgO heterostructure with θM = 84°, respectively. Field-free SOT switching is only observed as Ipulse is applied along [\(\bar{1}\)10]. e The schematic diagrams illustrate the switching of magnetization by SOT. The yellow arrow indicates the magnetization. The red arrow indicates the spin polarization \({{{{{\boldsymbol{\sigma }}}}}}\) provided by Pt as Ipulse is applied along [\(\bar{1}\)10] direction. The black curve arrow indicates the direction of magnetization relaxation. f Reversible field-free SOT switching with ±Jpulse about 5.7 × 1011 A/m2 and pulse width of 300 μs along \([\bar{1}10]\) in (110)-orientation Pt(5)/Co(0.6)/Pt(1.4)/NiO(20)/MgO heterostructure for more than 104 cycles. Values in parentheses are thickness in nm.
