This spin current magnetization rotational magnetoresistance effect element includes a substrate, a magnetoresistance effect element having a first ferromagnetic metal layer in which a direction of magnetization is fixed, a nonmagnetic layer, a second ferromagnetic metal layer configured for a direction of magnetization to be changed, and a cap layer in that order from the substrate side, and a spin-orbit torque wiring extending in a direction intersecting a lamination direction of the magnetoresistance effect element and joined to the cap layer, in which the cap layer includes one or more substances having high spin conductivity selected from the group consisting of Cu, Ag, Mg, Al, Si, Ge, and GaAs as a major component.

A spin current magnetization reversal element includes: a first ferromagnetic metal layer with a changeable magnetization direction; and a spin-orbit torque wiring, wherein a first direction is perpendicular to a surface of the layer, the wiring extends in a second direction intersecting the first and is bonded to the layer, wherein the wiring material is a binary alloy represented by the formula A.sub.xB.sub.1-x, a metal carbide, or metal nitride, wherein A is selected from Al, Ti, and Pt, and B is selected from Al, Cr, Mn, Fe, Co, Ni, Y, Ru, Rh, and Ir and the material has a cubic structure with symmetry of a space group Pm-3m or Fd-3m; or A is selected from Al, Si, Ti, Y, and Ta, and B is selected from C, N, Co, Pt, Au, and Bi and the material has a cubic structure with symmetry of a space group Fm-3m.

A nonmagnetic spacer layer in a magnetoresistive effect element includes a nonmagnetic metal layer that is formed of Ag and at least one of a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer. The first insertion layer and the second insertion layer include an Fe alloy that is expressed by Fe.sub.?X.sub.1-?. Here, X denotes one or more elements selected from a group consisting of O, Al, Si, Ga, Mo, Ag, and Au, and ? satisfies 0<?<1.

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.

The present invention relates to a spin torque oscillator with high power output and its applications. A spin torque oscillator may include a first magnetic reference layer having a fixed magnetization, a magnetic precession layer having a magnetization capable of precessing about an initial direction, and a first barrier layer interposed between the first magnetic reference layer and the magnetic precession layer. The first barrier layer is formed of an insulating material capable of inducing a negative differential resistance for the spin torque oscillator.

Magnetoresistive effect device including magnetoresistive effect element which high-frequency filter can be realized is provided. Magnetoresistive effect device includes: at least one magnetoresistive effect element including magnetization fixed, spacer, and magnetization free layer wherein magnetization direction is changeable; first and second ports; signal line; and direct-current input terminal. First and second ports are connected to each other via signal line. Magnetoresistive effect element is connected to signal line and is to be connected to ground in parallel to second port. Direct-current input terminal is connected to signal line. Closed circuit including magnetoresistive effect element, signal line, ground, and direct-current input terminal is to be formed. Magnetoresistive effect element is arranged wherein direct current input from direct-current input terminal flows through magnetoresistive effect element in direction from magnetization fixed layer to magnetization free layer.

An apparatus includes a spin torque oscillator, a sensor, and a processing unit. The spin torque oscillator is configured to receive a current and to generate a microwave output signal. The sensor is configured to detect the microwave output signal and to detect changes to frequency of the detected microwave output signal responsive to changes in an external magnetic field. The processing unit is configured to receive a sensed signal from the sensor. The processing unit is further configured to process the sensed signal and the changes to the frequency to determine magnitude and direction associated with the external magnetic field.

The present invention provides a high-frequency phase-locked oscillation circuit having an extremely narrow peak width and a stable frequency so that a high-frequency wave that is oscillated by the MR element solves a problem of a large peak width of oscillation spectrum. The high-frequency phase-locked oscillation circuit is achieved by providing: a magnetoresistive element 6 that oscillates a high-frequency wave with an oscillating frequency f.sub.out; a reference signal source 1 that outputs a reference signal with a reference frequency f.sub.ref; a phase-locked loop circuit having a phase comparator 3, a loop filer 4, and a frequency divider 9; an adder 5 that adds a phase error signal A output from the loop filter and a bias voltage B for oscillating the high-frequency wave from the magnetoresistive element, and that inputs an added bias voltage (A+B) to the magnetoresistive element 6; and a filter 7 provided between the frequency divider 9 and the magnetoresistive element 6 in a region closer to an input side of the frequency divider 9, the filter cutting off the reference frequency f.sub.ref while allowing the oscillating frequency f.sub.out to pass through the filter.

A device implemented based on the disclosed technology includes a thin-film magnetic structure that includes a substrate and thin film layers formed over the substrate to include a ferromagnetic layer formed over the substrate, and a non-magnetic dusting layer in contact with the ferromagnetic layer and structured to have a thickness around one molecular layer to enhance an interfacial perpendicular magnetic anisotropy energy density of the ferromagnetic layer.

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.