Magnetic properties and the interfacial Dzyaloshinskii-Moriya interaction in exchange biased Pt/Co/NixOy films

Current-Induced Manipulation of the Exchange Bias in a Pt/Co/NiO Structure

“…This process is caused by the presence of the interfacial Dzyaloshinskii−Moriya interaction (DMI), which determines the rotation direction of the magnetization in a homochiral domain wall. 24 In the previous work, the DMI constant in this system was measured: 19 Thus, the domain growth is caused by the perpendicular H z SOT field; meanwhile, the action of the in-plane fields H x and H x SOT defines the propagation direction of homochiral domain walls.…”

“…Depending on the orientation of the external magnetic field during layer deposition, the bias field can be directed both in the plane and perpendicular to the plane of the sample while maintaining the perpendicular magnetic anisotropy (PMA) in the ferromagnetic layer. It was expected that in the first case, the current-induced magnetization reversal would occur without an additional field, known as field-free switching. − In the second case, the current-induced hysteresis loop along the easy axis of magnetization should be shifted. However, it was found experimentally that regardless of the magnitude and orientation of the bias field, current-induced magnetization switching requires an additional external magnetic field H x and there is no current-induced shift on the hysteresis loops (Figure c).…”

“…The absence of a change in the bias field due to heating may be due to the difference in the process and method of preparing the NiO layer compared to this work. The parameters of NiO formation can significantly change the magnetic properties of the structure . However, it was shown in ref that the FM/AFM transition is subject to the training effect, which leads to degradation of the spin order in the AFM layer after 5–10 cycles of remagnetization.…”

“…A previous study of thin films with a Pt/Co/NiO layer composition showed that the maximum possible bias field is 24 mT. 19 Depending on the orientation of the external magnetic field during layer deposition, the bias field can be directed both in the plane and perpendicular to the plane of the sample while maintaining the perpendicular magnetic anisotropy (PMA) in the ferromagnetic layer. It was expected that in the first case, the current-induced magnetization reversal would occur without an additional field, known as field-free switching.…”

“…The parameters of NiO formation can significantly change the magnetic properties of the structure. 19 However, it was shown in ref 39 that the FM/AFM transition is subject to the training effect, which leads to degradation of the spin order in the AFM layer after 5−10 cycles of remagnetization.…”