A detection method and sensors are provided for the rapid detection of chemicals, biological and non-biological, and a wide range of viruses using magnetic tunnel junction-based molecular spintronics devices (MTJMSD) that produce unique magnetic resonance signals before and after interacting with target chemical, biochemical, viral, and other molecular agents.

A spin valve magnetoresistance element has an even number of free layer structures for which half has an antiferromagnetic coupling and the other half has a ferromagnetic coupling with respect to associated pinned layers. The different couplings are the result of an even number different spacer layers having respective different thicknesses.

A magnetoresistance element can have a substrate; a ferromagnetic seed layer consisting of a binary alloy of NiFe; and a first nonmagnetic spacer layer disposed under and directly adjacent to the ferromagnetic seed layer and proximate to the substrate, wherein the first nonmagnetic spacer layer is comprised of Ta or Ru. A method fabricating of fabricating a magnetoresistance element can include depositing a seed layer structure over a semiconductor substrate, wherein the depositing the seed layer structure includes depositing at least a ferromagnetic seed layer over the substrate. The method further can further include depositing a free layer structure over the seed layer structure, wherein the depositing the ferromagnetic seed layer comprises depositing the ferromagnetic seed layer in the presence of a motion along a predetermined direction and in the presence of a predetermined magnetic field having the same predetermined direction.

A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer. The magnetic element can further include a ferromagnetic amorphous seed layer.

A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer. The magnetic element can further include a ferromagnetic amorphous seed layer.

According to one embodiment, an oscillator includes first to third conductive bodies, a first stacked unit, and a magnetic unit. The first conductive body includes first, second region, and third regions. The second conductive body includes a portion separated from the third region. The first stacked unit is provided between the third region and the portion. The first stacked unit includes first to fourth magnetic layers, and first to third intermediate layers. At least a portion of the magnetic unit and at least a portion of the first stacked unit overlap each other. In a first state, the first to fourth magnetizations are aligned with a third direction perpendicular to the first direction and the second direction. The second magnetization has a component in a reverse orientation of the first magnetization. The fourth magnetization has a component in a reverse orientation of the third magnetization.

Exemplary embodiments are directed to magnetoresistive sensors and corresponding fabrication methods for magnetoresistive sensors. One example of a magnetoresistive sensor includes a layer stack, wherein the layer stack includes a reference layer having a fixed reference magnetization, wherein the fixed reference magnetization has a first magnetic orientation. The layer stack furthermore includes a magnetically free system of a plurality of layers, wherein the magnetically free system has a magnetically free magnetization, wherein the magnetically free magnetization is variable in the presence of an external magnetic field, and wherein the magnetically free magnetization has a second magnetic orientation in a ground state. The magnetically free system has two ferromagnetic layers and an interlayer, wherein the interlayer is arranged between the two ferromagnetic layers and includes magnesium oxide. The layer stack furthermore includes a barrier layer, which is arranged between the reference layer and the magnetically free system and includes magnesium oxide.

In one aspect, a dual tunnel magnetoresistance (TMR) element structure includes a first TMR element and a second TMR element. The TMR element structure also includes a conducting layer that is disposed between the first TMR element and the second TMR element and is in direct contact with the first TMR element and the second TMR element.

A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer. The magnetic element can further include a ferromagnetic amorphous seed layer.

Provided is a magnetoresistance effect element in which the magnetization direction of the recording layer is perpendicular to the film surface and which has a high thermal stability factor Δ, and a magnetic memory. A recording layer having a configuration of first magnetic layer/first non-magnetic coupling layer/first magnetic insertion layer/second non-magnetic coupling layer/second magnetic layer is sandwiched between the first and second non-magnetic layers and stacked so that a magnetic coupling force is generated between the first magnetic layer and the second magnetic layer.