초록

Techniques and magnetic devices associated with a magnetic element that includes a fixed layer having a fixed layer magnetization and perpendicular anisotropy, a nonmagnetic spacer layer, and a free layer having a changeable free layer magnetization and perpendicular anisotropy.

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1. A device, comprising: a magnetic element including: a fixed layer having a fixed layer magnetization fixed in a direction perpendicular to the fixed layer;a free layer that is parallel with the fixed layer and has a free layer magnetization that is perpendicular to the free layer and is changeabl

1. A device, comprising: a magnetic element including: a fixed layer having a fixed layer magnetization fixed in a direction perpendicular to the fixed layer;a free layer that is parallel with the fixed layer and has a free layer magnetization that is perpendicular to the free layer and is changeable relative to the fixed layer magnetization;a nonmagnetic spacer layer between the fixed layer and the free layer;a first interfacial layer in contact with the nonmagnetic spacer layer and between the fixed layer and the nonmagnetic spacer layer, the first interfacial layer having a native magnetization which is, in the absence of coupling with other layers, parallel to the first interfacial layer and perpendicular to the fixed layer;a connecting layer between and in contact with both the first interfacial layer and the fixed layer, the connecting layer being structured (i) to induce perpendicular anisotropy in the first interfacial layer and (ii) to provide magnetic coupling between the fixed layer and the first interfacial layer, such that (i) the induced perpendicular anisotropy together with (ii) the magnetic coupling change the magnetization of the first interfacial layer from being parallel to the first interfacial layer to being perpendicular to the first interfacial layer; anda second interfacial layer between and in contact with both the non-magnetic spacer layer and the free layer, the second interfacial layer being magnetically coupled with the free layer. 2. The device as in claim 1, wherein the connecting layer is a crystalline material that includes MgO. 3. The device as in claim 2, wherein the connecting layer is structured to have a resistance-area product less than a resistance-area product of the spacer layer. 4. The device as in claim 2, wherein the connecting layer is made from one combinations of MgO and Mn, MgO and Cr, MgO and V, MgO and Ta, MgO and Pd, MgO and Pt, MgO and Ru, and MgO and Cu. 5. The device as in claim 1, wherein the connecting layer is an amorphous material. 6. The device as in claim 5, wherein the connecting layer is made from an oxide. 7. The device as in claim 6, wherein the oxide is one of silicon oxide, aluminum oxide, or titanium oxide. 8. The device as in claim 5, wherein the connecting layer is made from a nitride. 9. The device as in claim 8, wherein the nitride is one of titanium nitride, tantalum nitride, copper nitride, or silicon nitride. 10. The device as in claim 1, wherein the connecting layer is a crystalline metal selected from the group consisting of Mn, Cr, V, Ru, Cu, Pt, Pd or Ta. 11. The device as in claim 1, wherein: the connecting layer is a crystalline material that comprises MgO, andthe first interfacial layer comprises CoFeB. 12. The device as in claim 1, wherein the first and second interfacial layers each has a lattice structure that is compatible to a lattice structure of the nonmagnetic spacer layer. 13. The device as in claim 1, wherein the first and second interfacial layers each comprises Fe and Co. 14. The device as in claim 1, wherein the first interfacial layer comprises CoFeB. 15. The device as in claim 1, wherein the first and second interfacial layers each has a thickness larger than 1 nanometer. 16. The device as in claim 15, wherein the second interfacial layer has the thickness larger than 2 nanometers. 17. The device as in claim 1, wherein the fixed layer has a thickness larger than the thickness of the first interfacial layer and the free layer has a thickness larger than the thickness of the second interfacial layer. 18. The device as in claim 1, wherein the second interfacial layer is magnetically coupled with the free layer such that a magnetization of the second interfacial layer is parallel to the free layer magnetization. 19. The device as in claim 18, wherein the second interfacial layer has a native magnetization which is, in absence of interaction with the free layer, parallel to the second interfacial layer and perpendicular to the fixed layer magnetization. 20. The device as in claim 19, wherein the second interfacial layer comprises CoFeB. 21. The device of claim 1, wherein: the free layer includes at least one ferromagnetic material Ni, Fe, Co, or combinations thereof; Pd, Pt, or combinations thereof; and combined with at least one nonmagnetic material X;wherein an atomic percentage of free layer ferromagnetic material Ni, Fe, Co, or combinations thereof equals an atomic percentage of free layer material Pd, Pt, or combinations thereof;wherein the free layer includes between zero and fifty atomic percent of nonmagnetic material X;wherein X includes at least one of Ti, Zr, Hf; V, Nb, Ta, Cr, Mo, W, Pt, Pd, Ir, Rh, Ru, Os, Re, Au, Ag, Cu, B, C, N, O, Al, Si, P, S, Ga, Ge, In, Sn, Gd, Tb, Dy, Ho, Nd, or a transition metal silicide. 22. The device of claim 1, wherein: the free layer includes at least one ferromagnetic material Ni, Fe, Co, or combinations thereof; Pd, Pt, or combinations thereof; and combined with at least two nonmagnetic materials X1 and X2;wherein an atomic percentage of free layer ferromagnetic material Ni, Fe, Co, or combinations thereof equals an atomic percentage of free layer material Pd, Pt, or combinations thereof;wherein the free layer includes between zero and fifty atomic percent of nonmagnetic material X1;wherein the free layer includes between zero and fifty atomic percent of nonmagnetic material X2;wherein X1 includes at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Pt, Pd, Ir, Rh, Ru, Os, Re, Au, Ag, Cu, Gd, Tb, Dy, Ho, Nd;wherein X2 includes at least one of B, C, N, O, Al, Si, P, S, Ga, Ge, In, Sn, or a transition metal silicide. 23. The device of claim 1, wherein the fixed layer comprises two magnetic sublayers separated by a non-magnetic layer, such that the two magnetic sublayers are antiferromagnetically coupled. 24. The device of claim 1, wherein the fixed layer comprises two magnetic sublayers separated by an oxide layer, such that the two magnetic sublayers are antiferromagnetically coupled. 25. The device as in claim 1 further comprising: a substrate on which the magnetic element is formed;a capping layer; anda seed layer, wherein if the fixed layer is placed between the free layer and the substrate, then the capping layer is over the free layer, and the seed layer is between the substrate and the fixed layer, elseif the free layer is placed between the fixed layer and the substrate, then the capping layer is over the fixed layer, and the seed layer is between the substrate and the free layer. 26. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises a multilayer structure. 27. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises crystalline structure. 28. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises amorphous structure. 29. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises a metal. 30. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises an oxide. 31. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises nonmagnetic material. 32. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises magnetic material. 33. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises in-plane anisotropy. 34. The device as in claim 25, wherein either the capping layer or the seed layer or both comprises perpendicular anisotropy. 35. The device as in claim 1 further comprising: a circuit that is coupled to the magnetic element and supplies a current to flow through layers of the magnetic element in a direction perpendicular to the layers to switch the magnetization of the free layer. 36. A device, comprising: a magnetic element array including: a substrate; anda plurality of magnetic elements formed on the substrate, each magnetic element comprising a fixed layer having a fixed layer magnetization fixed in a direction perpendicular to the fixed layer,a free layer that is parallel with the fixed layer and has a free layer magnetization that is perpendicular to the free layer and is changeable relative to the fixed layer magnetization,a nonmagnetic spacer layer between the fixed layer and the free layer;a first interfacial layer in contact with the nonmagnetic spacer layer and between the fixed layer and the nonmagnetic spacer layer, the first interfacial layer having a native magnetization which is, in the absence of coupling with other layers, parallel to the first interfacial layer and perpendicular to the fixed layer,a connecting layer between and in contact with both the first interfacial layer and the fixed layer, the connecting layer being structured (i) to induce perpendicular anisotropy in the first interfacial layer and (ii) to provide magnetic coupling between the fixed layer and the first interfacial layer, such that (i) the induced perpendicular anisotropy together with (ii) the magnetic coupling change the magnetization of the first interfacial layer from being parallel to the first interfacial layer to being perpendicular to the first interfacial layer, anda second interfacial layer between and in contact with both the non-magnetic spacer layer and the free layer, the second interfacial layer being magnetically coupled with the free layer; anda circuit that is coupled to the magnetic element array and supplies a current to flow through layers of each magnetic element in a direction perpendicular to the layers to switch the magnetization of the free layer based on spin torque transfer between two magnetization directions. 37. The device as in claim 36, wherein the connecting layer is a crystalline material that includes MgO. 38. The device as in claim 36, wherein the first and second interfacial layers each comprises CoFeB. 39. The device as in claim 36, wherein the first and second interfacial layers each has a thickness larger than 1 nanometer. 40. The device as in claim 39, wherein the second interfacial layer has the thickness larger than 2 nanometers. 41. The device as in claim 36, wherein the fixed layer has a thickness larger than the thickness of the first interfacial layer and the free layer has a thickness larger than the thickness of the second interfacial layer. 42. A device, comprising: a magnetic element including: a fixed layer having a fixed layer magnetization fixed in a direction perpendicular to the fixed layer;a free layer that is parallel with the fixed layer and has a free layer magnetization that is perpendicular to the free layer and is changeable relative to the fixed layer magnetization;a nonmagnetic spacer layer between the fixed layer and the free layer;a first interfacial layer between the fixed layer and the nonmagnetic spacer layer and in contact with the nonmagnetic spacer layer, the interfacial layer comprising CoFeB with a native magnetization which is, in absence of coupling with other layers, parallel to the interfacial layer and perpendicular to the fixed layer magnetization;a connecting layer between and in contact with both the first interfacial layer and the fixed layer, the connecting layer being a crystalline material that includes MgO which induces perpendicular anisotropy in the first interfacial layer, such that the magnetization of the first interfacial layer having the induced perpendicular anisotropy changes, via magnetic coupling with the fixed layer, from being parallel to the first interfacial layer to being perpendicular to the first interfacial layer; anda second interfacial layer between and in contact with both the non-magnetic spacer layer and the free layer, the second interfacial layer being magnetically coupled with the free layer;a substrate on which the magnetic element is formed to place the fixed layer between the free layer and the substrate or to place the free layer between the fixed layer and the substrate; anda circuit that is coupled to the magnetic element and supplies a current to flow through layers of the magnetic element in a direction perpendicular to the layers to switch the magnetization of the free layer.