Provided are magnetoresistance effect element and a Heusler alloy in which an amount of energy required to rotate magnetization can be reduced. The magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co.sub.2Fe.sub.αZ.sub.β is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Mn, Cr, Al, Si, Ga, Ge, and Sn, α and β satisfy 2.3≤α+β, α<β, and 0.5<α<1.9, and the substitution element is an element different from the Z element and has a smaller magnetic moment than Co.

In one embodiment, the magnetic memory device includes a free layer structure having a variable magnetization direction. The free layer structure includes a first free layer, the first free layer being a first Heusler alloy; a coupling layer on the first free layer, the coupling layer including a metal oxide layer; and a second free layer on the metal oxide layer, the second free layer being a second Heusler alloy, the second Heusler alloy being different from the first Heusler alloy.

A device including a multi-layered structure that includes: a first layer that includes a first magnetic Heusler compound; a second layer that is non-magnetic at room temperature and includes both Ru and at least one other element E, wherein the composition of the second layer is represented by Ru1−xEx, with x being in the range from 0.45 to 0.55; and a third layer including a second magnetic Heusler compound. The multi-layered structure may overlay a substrate. The device may include a tunnel barrier overlying the multi-layered structure.

A magnetoresistance effect element and a Heusler alloy in which a state change due to annealing does not easily occur. The element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co.sub.2Fe.sub.αZ.sub.β is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Al, Si, Ga, Ge, and Sn, α and β satisfy 2.3≤α+β, α<β, and 0.5<α<1.9, and the substitution element is one or more elements selected from the group consisting of elements having a melting point higher than that of Fe among elements of Groups 4 to 10.

The invention relates to hard magnets that include an intermetallic compound having the general composition
X.sub.aX′.sub.bY.sub.cZ.sub.d where X and X′ independently from one another are representative of a 3d transition metal with unpaired electrons; Y is a 4d or 5d transition metal of groups 5, 8, 9, or 10 Z is a main group element of groups 13, 14 or 15; a and d independently from one another represent a number between 0.1 and 2.0; and b and c independently from one another represent a number between 0.0 and 2.0; such that a+b+c+d is between 3.0 and 4.0.

A method for tuning the frequency of THz radiation is provided. The method utilizes an apparatus comprising a spin injector, a tunnel junction coupled to the spin injector, and a ferromagnetic material coupled to the tunnel junction. The ferromagnetic material comprises a Magnon Gain Medium (MGM). The method comprises the step of applying a bias voltage to shift a Fermi level of the spin injector with respect to the Fermi level of the ferromagnetic material to initiate generation of non-equilibrium magnons by injecting minority electrons into the Magnon Gain Medium. The method further comprises the step of tuning a frequency of the generated THz radiation by changing the value of the bias voltage.

Ferromagnetic materials are disclosed that comprise at least one Dirac half metal material. In addition, Dirac half metal materials are disclosed, wherein the material comprises a plurality of massless Dirac electrons. In addition, ferromagnetic materials are disclosed that includes at least one Dirac half metal material, wherein the material comprises a plurality of massless Dirac electrons, wherein the material exhibits 100% spin polarization, and wherein the plurality of electrons exhibit ultrahigh mobility. Spintronic devices and heterostructures are also disclosed that include a Dirac half metal material.

An apparatus is provided to improve spin injection efficiency from a magnet to a spin orbit coupling material. The apparatus comprises: a first magnet; a second magnet adjacent to the first magnet; a first structure comprising a tunneling barrier; a third magnet adjacent to the first structure; a stack of layers, a portion of which is adjacent to the third magnet, wherein the stack of layers comprises spin-orbit material; and a second structure comprising magnetoelectric material, wherein the second structure is adjacent to the first magnet.

Ferromagnetic materials are disclosed that comprise at least one Dirac half metal material. In addition, Dirac half metal materials are disclosed, wherein the material comprises a plurality of massless Dirac electrons. In addition, ferromagnetic materials are disclosed that includes at least one Dirac half metal material, wherein the material comprises a plurality of massless Dirac electrons, wherein the material exhibits 100% spin polarization, and wherein the plurality of electrons exhibit ultrahigh mobility. Spintronic devices and heterostructures are also disclosed that include a Dirac half metal material.

An apparatus is provided which comprises: a magnetic junction including: a first structure comprising a magnet with an unfixed perpendicular magnetic anisotropy (PMA) relative to an x-y plane of a device; a second structure comprising one of a dielectric or metal; a third structure comprising a magnet with fixed PMA, wherein the third structure has an anisotropy axis perpendicular to the plane of the device, and wherein the third structure is adjacent to the second structure such that the second structure is between the first and third structures; a fourth structure comprising an antiferromagnetic (AFM) material, the fourth structure adjacent to the third structure; a fifth structure comprising a magnet with PMA, the fifth structure adjacent to the fourth structure; and an interconnect adjacent to the first structure, the interconnect comprising spin orbit material.