The present disclosure generally relates to a bismuth antimony (BiSb) based STO (spin torque oscillator) sensor. The STO sensor comprises a SOT device and a magnetic tunnel junction (MTJ) structure. By utilizing a BiSb layer within the SOT device, a larger spin Hall angle (SHA) can be achieved, thereby improving the efficiency and reliability of the STO sensor.

The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.

The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, the tunnel barrier layer is expressed by a chemical formula of AB.sub.2O.sub.x, and has a spinel structure in which cations are arranged in a disordered manner, A represents a divalent cation that is either Mg or Zn, and B represents a trivalent cation that includes a plurality of elements selected from the group consisting of Al, Ga, and In.

The present disclosure provides: a magnetoresistive element having a large magnetoresistance change ratio (MR ratio); and a magnetic sensor, a reproducing head and a magnetic recording and reproducing device. The magnetoresistive element comprises a magnetoresistive film including a pair of body centered cubic (bcc) crystal structure CoFe ferromagnetic layers with a (001) crystal orientation, the pair of layers separated by a non-magnetic layer of Cu with bcc crystal structure.

The present disclosure generally relates to a read head assembly having a dual free layer (DFL) structure disposed between a first shield and a second shield at a media facing surface. The read head assembly further comprises a rear hard bias (RHB) structure disposed adjacent to the DFL structure recessed from the media facing surface, where an insulation layer separates the RHB structure from the DFL structure. The insulation layer is disposed perpendicularly between the first shield and the second shield. The DFL structure comprises a first free layer and a second free layer having equal stripe heights from the media facing surface to the insulation layer. The RHB structure comprises a seed layer, a bulk layer, and a capping layer. The capping layer and the insulation layer prevent the bulk layer from contacting the second shield.

A 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, and at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy represented by the following General Formula (1):

Co.sub.2Fe.sub.αX.sub.β  (1)

(in Formula (1), X represents one or more elements selected from the group consisting of Mn, Cr, Si, Al, Ga and Ge, and α and β represent numbers that satisfy 2.3≤α+β, α<β, and 0.5<α<1.9).

A stacked structure is positioned on a nonmagnetic metal layer. The stacked structure includes a ferromagnetic layer and an intermediate layer interposed between the nonmagnetic metal layer and the ferromagnetic layer. The intermediate layer includes a NiAlX alloy layer represented by Formula (1): Ni.sub.γ1Al.sub.γ2X.sub.γ3 . . . (1), [X indicates one or more elements selected from the group consisting of Si, Sc, Ti, Cr, Mn, Fe, Co, Cu, Zr, Nb, and Ta, and satisfies an expression of 0<γ<0.5 in a case of γ=γ3/(γ1+γ2+γ3)].

A frequency sensor is provided. The frequency sensor may include: a magnetoresistive nano-oscillator including a magnetic heterostructure of at least a magnetic free layer, a magnetic reference layer and a non-magnetic intermediate layer arranged between the magnetic free layer and the magnetic reference layer; a coupling arrangement for coupling an incoming signal to at least one magnetic mode of the magnetic free layer, and a frequency estimator. The frequency estimator may be configured to: perform a plurality of voltage measurements across the magnetoresistive nano-oscillator over time; calculate a time averaged voltage across the magnetoresistive nano-oscillator based on the plurality of voltage measurements; estimate, over a finite range of frequencies, a frequency of the incoming signal based on the calculated time averaged voltage, and output a signal representative of the estimated frequency. A method of estimating a frequency of an incoming signal is also provided.

A 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, and at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy represented by the following General Formula (1):
Co.sub.2Fe.sub.αX.sub.β  (1)
(in Formula (1), X represents one or more elements selected from the group consisting of Mn, Cr, Si, Al, Ga and Ge, and α and β represent numbers that satisfy 2.3≤α+β, α<β, and 0.5<α<1.9).