A spin torque oscillator includes a first electrode, a second electrode and a device layer stack located between the first electrode and the second electrode. The device layer stack includes a spin polarization layer including a first ferromagnetic material, an assist layer including a third ferromagnetic material, a ferromagnetic oscillation layer including a second ferromagnetic material located between the spin polarization layer and the assist layer, a nonmagnetic spacer layer located between the spin polarization layer and the ferromagnetic oscillation, and a nonmagnetic coupling layer located between the ferromagnetic oscillation layer and the assist layer. The assist layer is antiferromagnetically coupled to the ferromagnetic oscillation layer through the non-magnetic coupling layer, and the assist layer has a magnetization that is coupled to a magnetization of the ferromagnetic oscillation layer.

A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.

Disclosed is a method for generating, from a first electric current having a first frequency, a plurality of second currents each having a second respective frequency component, the method including the following steps: supplying a frequency distributor including a first set of pillars including a layer made from a first magnetic material and having a resonance frequency; exciting each pillar of the first set with an electromagnetic field having the first frequency, the ratio between twice the resonance frequency of each pillar of the first set and the first frequency being equal, to within ten percent, to a first natural integer; and generating, by each pillar of the first set, a second frequency component in the second respective current.

A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a magnetic tunnel junction (MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A passivation layer that is a single layer or multilayer comprising one of B, C, or Ge, or an alloy thereof wherein the B, C, and Ge content, respectively, is at least 10 atomic % is formed on the MTJ sidewall to protect the MTJ from reactive species during subsequent processing including deposition of a dielectric layer that electrically isolates the MTJ from adjacent MTJs, and during annealing steps around 400° C. in CMOS fabrication. The single layer is about 3 to 10 Angstroms thick and may be an oxide or nitride of B, C, or Ge. The passivation layer is preferably amorphous to prevent diffusion of reactive oxygen or nitrogen species.

This spin current magnetization rotational type magnetoresistive element includes a magnetoresistive effect element having a first ferromagnetic metal layer having a fixed magnetization orientation, a second ferromagnetic metal layer having a variable magnetization orientation, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a direction that intersects the stacking direction of the magnetoresistive effect element, and is connected to the second ferromagnetic metal layer, wherein the electric current that flows through the magnetoresistive effect element and the electric current that flows through the spin-orbit torque wiring merge or are distributed in the portion where the magnetoresistive effect element and the spin-orbit torque wiring are connected.

In example embodiments, an RF-to-DC converter includes one or more unit cells that integrate a spintronic element (e.g., a magnetic tunnel junction (MTJ)) into a conductor ring RF energy absorber (e.g., a split-ring resonator (SRR)). A RF-to-DC converter that includes one or more MTJ-integrated SRR unit cells may provide compactness, as each unit cell includes its own independent SRR and integrated MTJ; scalability, as multiple unit cells may be connected into an array to increase DC power output; and energy harvesting efficiency, as a MTJ may be much more sensitive than a Schottky diode and the SRR of each unit cell may directly feed energy to a MTJ without impedance matching circuits.

A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.

A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a magnetic tunnel junction (MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A passivation layer that is a single layer or multilayer comprising one of B, C, or Ge, or an alloy thereof wherein the B, C, and Ge content, respectively, is at least 10 atomic % is formed on the MTJ sidewall to protect the MTJ from reactive species during subsequent processing including deposition of a dielectric layer that electrically isolates the MTJ from adjacent MTJs, and during annealing steps around 400° C. in CMOS fabrication. The single layer is about 3 to 10 Angstroms thick and may be an oxide or nitride of B, C, or Ge. The passivation layer is preferably amorphous to prevent diffusion of reactive oxygen or nitrogen species.

A magnetic structure is provided. The magnetic structure may have a first magnetic layer with a first magnetization direction, a second magnetic layer with a second magnetization direction and a coupling layer interposed between the first and second magnetic layers. The coupling layer may include at least one non-magnetic element and at least one magnetic element. The atomic ratio of the at least one non-magnetic element to the at least one magnetic element is (100−x):x, where x is an atomic concentration parameter. Atomic concentration parameter, x, may cause the first magnetic layer to be non-collinearly coupled to the second magnetic layer such that, in the absence of external magnetic field, the first magnetization direction is oriented at a non-collinear angle relative to the second magnetization direction.

A method and system for generating voltage and/or current oscillations in a single magnetic layer is provided. The method comprises applying a direct voltage/current to the layer in a longitudinal direction; and developing a longitudinal voltage between a pair of longitudinal voltage leads and/or a transverse voltage between a pair of transverse voltage leads. The magnetic layer comprises a ferrimagnetic or antiferrimagnetic material having a first and second magnetic sub-lattice, wherein the first sub-lattice is a dominant sub-lattice such that the charge carriers at the Fermi energy originate predominantly from the dominant sub-lattice and the charge carriers at the Fermi energy are spin polarised. In some embodiments, the dominant current carrying sub-lattice may lack inversion symmetry.