Magnetic multilayer device, method for producing such a device, magnetic field sensor, magnetic memory and logic gate using such a device
AssigneesCommissariat a l'Energie Atomique, Centre National De La Recherche Scientifique
InventorsBernard Rodmacq, Stéphane Auffret, Bernard Dieny, Jérôme Moritz
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Abstract
This magnetic multilayer device comprises, on a substrate, an alternating sequence of magnetic metallic layers M and oxide, hydride or nitride layers O. The number of layers M equals at least two. The layers M are continuous. There is interfacial magnetic anisotropy perpendicular to the plane of the layers at the level of the M/O interfaces.
Claims22
A magnetic multilayer device comprising, on a substrate, an alternating sequence of magnetic metallic layers M and oxide, hydride or nitride layers O, wherein:
- the number of layer M equals at least two;
- the layers M are continuous, have a thickness ranging between 0.3 and 5 nm, and, in the absence of an applied magnetic field, have their magnetization parallel to the plane of the layer in the absence of layers O because of shape anisotropy;
- in a temperature range equal to or larger than ambient temperature, there occurs interfacial magnetic anisotropy perpendicular to the plane of the layers at the M/O and O/M interfaces, able to surpass the shape anisotropy and orient the magnetization axis of layers M in a direction substantially perpendicular to the plane of the layers in the absence of any external magnetic field;
- the magnetic metallic layers consist of a magnetic element, a magnetic alloy or a multilayer formed by an alternating sequence of non-magnetic and magnetic materials, the latter being selected from the group consisting of Fe, Ni, Co or alloys thereof;
- and
- the oxide, hydride or nitride layers O have a thickness of at least 0.3 nm and are based on elements selected from the group consisting of Al, Mg, Ru, Ta, Cr, Zr, Hf, Ti, V, Si, Cu, W or alloys thereof.
A magnetic multilayer device comprising:
- a substrate;
- an alternating sequence of magnetic metallic layers M and oxide, hydride or nitride layers O, the number of layer M equals at least two, the layers M are continuous, have a thickness ranging between 0.3 and 5 nm, and are formed of a magnetic material having its magnetization parallel to the plane of the layer in the absence of layers O and any applied magnetic field because of shape anisotropy,
- wherein in a temperature range equal to or larger than ambient temperature, there occurs interfacial magnetic anisotropy perpendicular to the plane of the layers at the M/O and O/M interfaces, able to surpass the shape anisotropy and orient the magnetization of layers M in a direction substantially perpendicular to the plane of the layers M in the absence of an external magnetic field,
- wherein the magnetic multilayer device exhibits a Hall resistivity associated with a longitudinal resistivity of the order of 1000 μΩcm and has two stable magnetic states in the absence of any applied magnetic field,
- wherein the magnetic metallic layers consist of a magnetic element, a magnetic alloy or a multilayer formed by an alternating sequence of non-magnetic and magnetic materials, the latter being selected from the group consisting of Fe, Ni, Co or alloys thereof, and
- wherein the oxide, hydride or nitride layers O have a thickness of at least 0.3 nm and are based on elements selected from the group consisting of Al, Mg, Ru, Ta, Cr, Zr, Hf, Ti, V, Si, Cu, W or alloys thereof.
Dependencies are inferred from the claim text.