10:30 〜 10:45
▲ [14a-2J-7] Voltage-induced magnetic anisotropy change of Fe-4f-metal alloys
キーワード：TMR,voltage effect,MTJ
Voltage-induced magnetic anisotropy change has been investigated because of its potential for non-volatile magnetic random access memories with low power operation. [1,2] Since spin-orbit coupling plays an important role in the voltage-induced anisotropy change, in our previous study, we tested 4f-metals since 4f metals have large orbital moment. In FeGd alloys, large anisotropy field change and magnetization-energy change ratio have been observed [3]. This suggests that 4f-metals are promising for voltage-induced spintronics devices. In this study, we investigated voltage-inducecd anisotropy change of FeTb(Nd)|MgO|-based magnetic tunnel junctions (MTJs).
V (30 nm)|Fe100-x(Gdx, Tbx Ndx) [x = 0-30]|MgO (1.6 nm)|Fe (10 nm) multilayer was fabricated by molecular beam epitaxy method on MgO [001] substrate as shown in Fig. 1. The Fe-4f metal alloy layer was prepared using co-evaporation of pure Fe and 4f metals. The film was patterned into MTJs by using electron-beam lithography and an Ar ion-milling. Fig. 2 shows the normalized magnetization curve of Fe (0.55 nm), Fe90Gd10 (0.60 nm) and Fe90Tb10 (0.64 nm) at 0.3 V (-0.3 V), which is calculated by magnetization curve. From this, the anisotropy field changes of Fe90Gd10 and Fe90Tb10 are larger than that of Fe.
This work was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan)
V (30 nm)|Fe100-x(Gdx, Tbx Ndx) [x = 0-30]|MgO (1.6 nm)|Fe (10 nm) multilayer was fabricated by molecular beam epitaxy method on MgO [001] substrate as shown in Fig. 1. The Fe-4f metal alloy layer was prepared using co-evaporation of pure Fe and 4f metals. The film was patterned into MTJs by using electron-beam lithography and an Ar ion-milling. Fig. 2 shows the normalized magnetization curve of Fe (0.55 nm), Fe90Gd10 (0.60 nm) and Fe90Tb10 (0.64 nm) at 0.3 V (-0.3 V), which is calculated by magnetization curve. From this, the anisotropy field changes of Fe90Gd10 and Fe90Tb10 are larger than that of Fe.
This work was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan)