Perpendicular magnetic layer and magnetic device including the same
Embodiments of the inventive concepts provide a flat perpendicular magnetic layer having a low saturation magnetization and a perpendicular magnetization-type tunnel magnetoresistive element using the same. The perpendicular magnetic layer is a nitrogen-poor (Mn 1−x Ga x )N y layer (0<x≤0.5 and 0<y<0.1) formed by providing nitrogen (N) into a MnGa alloy while adjusting a nitrogen amount. The perpendicular magnetic layer can be formed flat.
1. A perpendicular magnetic layer comprising:
a composition represented by a chemical formula of (Mn 1−x M x )N y where ‘M’ is at least one of gallium (Ga) or germanium (Ge), 0<x≤0.5, and 0.005 ≤y<0.1,
wherein the composition has a D0 22 or L1 0 crystal structure.
2. The perpendicular magnetic layer of claim 1 , wherein 0.2<x<0.4.
3. The perpendicular magnetic layer of claim 1 , wherein 0.005≤y<0.05.
4. The perpendicular magnetic layer of claim 1 , wherein 0.005≤y<0.02.
5. The perpendicular magnetic layer of claim 1 , wherein the perpendicular magnetic layer is vapor-grown on a substrate.
6. The perpendicular magnetic layer of claim 5 , wherein the substrate is a single-crystalline substrate having a cubic system structure having a (001) plane orientation or a layer having a cubic system structure having a (001) plane orientation.
7. The perpendicular magnetic layer of claim 1 , wherein the perpendicular magnetic layer is vapor-grown on an underlayer.
8. The perpendicular magnetic layer of claim 7 , wherein the underlayer is a non-magnetic layer grown in a single-crystalline state or an electrically conductive layer grown in a single-crystalline state.
9. A magnetic device comprising:
a first perpendicular magnetic layer disposed on a substrate,
wherein the first perpendicular magnetic layer is represented by a chemical formula of (Mn 1−x M x )N y where ‘M’ is at least one of gallium (Ga) or germanium (Ge), 0<x≤0.5, and 0.005≤y<0.1, and
wherein the first perpendicular magnetic layer has a D0 22 or L1 0 crystal structure.
10. The magnetic device of claim 9 , further comprising:
an underlayer between the substrate and the first perpendicular magnetic layer,
wherein the underlayer is a single-crystalline non-magnetic layer or a single-crystalline conductive layer.
11. The magnetic device of claim 9 , further comprising:
a non-magnetic layer on the first perpendicular magnetic layer.
12. The magnetic device of claim 11 , further comprising:
an insertion layer disposed between the non-magnetic layer and the first perpendicular magnetic layer, the insertion layer having a cubic system structure having a (001) plane orientation.
13. The magnetic device of claim 11 , further comprising:
a second perpendicular magnetic layer on the non-magnetic layer.
14. The magnetic device of claim 13 , wherein the second perpendicular magnetic layer is represented by a chemical formula of (Mn 1−x M x )N y where ‘M’ is at least one of gallium (Ga) or germanium (Ge), 0<x0.5, and 0.005 ≤y<0.1, and
wherein the second perpendicular magnetic layer has a D0 22 or L1 0 crystal structure.
15. The magnetic device of claim 13 , wherein the second perpendicular magnetic layer includes a different material from the first perpendicular magnetic layer.
16. The magnetic device of claim 13 , further comprising:
an upper electrode on the second perpendicular magnetic layer.
17. The perpendicular magnetic layer of claim 1 , wherein the composition includes a composition ratio of Mn to Ga that is 75%:25%.
18. The perpendicular magnetic layer of claim 1 , wherein the composition includes a composition ratio of Mn to Ga that is 71%:29%.
19. The magnetic device of claim 9 , wherein the first perpendicular magnetic layer includes a composition ratio of Mn to Ga that is 75% : 25%.
20. The magnetic device of claim 9 , wherein the first perpendicular magnetic layer includes a composition ratio of Mn to Ga that is 71%:29%.