Abstract: The disclosure is directed to an iron-nitride material having a polycrystalline microstructure including a plurality of elongated crystallographic grains with grain boundaries, the iron-nitride material including at least one of an ??-Fe16N2 phase and a body-center-tetragonal (bct) phase comprising Fe and N. The disclosure is also directed a method producing an iron-nitride material.

Abstract: A semiconductor device includes a substrate having an array region defined thereon, a ring of magnetic tunneling junction (MTJ) region surrounding the array region, a gap between the array region and the ring of MTJ region, and metal interconnect patterns overlapping part of the ring of MTJ region. Preferably, the array region includes a magnetic random access memory (MRAM) region and a logic region and the ring of MTJ region further includes a first MTJ region and a second MTJ region extending along a first direction and a third MTJ region and a fourth MTJ region extending along a second direction.

Abstract: All example composition may include a plurality of grains including an iron nitride phase. The plurality of grains may have an average wain size between about 10 nm and about 200 nm. An example technique may include treating a composition including a plurality of grains including au iron-based phase to adjust an average grain size of the plurality of grains to between about 20 nm and about 100 ma. The example technique may include nitriding the plurality of grains to form or grow an iron nitride phase.

Abstract: A circuit includes a first two-state device, a second two-state device and a third two-state device, each two-state device having a first resistance in a first state and a second resistance in a second state. First control elements are configured to apply a first voltage to the first two-state device to stochastically place the first two-state device in either the first state or the second state. Second control elements are configured to apply a second voltage to the second two-state device to stochastically place the second two-state device in either the first state or the second state. Third control elements are configured to send respective currents through the first two-state device and the second two-state device so as to place the third two-state device in either the first state or the second state based on the state of the first two-state device and the state of the second two-state devices.

Abstract: Example nanoparticles may include an iron-based core, and a shell. The shell may include a non-magnetic, anti-ferromagnetic, or ferrimagnetic material. Example alloy compositions may include an iron-based grain, and a grain boundary. The grain boundary may include a non-magnetic, anti-ferromagnetic, or ferrimagnetic material. Example techniques for forming iron-based core-shell nanoparticles may include depositing a shell on an iron-based core. The depositing may include immersing the iron-based core in a salt composition for a predetermined period of time. The depositing may include milling the iron-based core with a salt composition for a predetermined period of time. Example techniques for treating a composition comprising core-shell nanoparticles may include nitriding the composition.

Abstract: The disclosure is directed to an iron-nitride material having a polycrystalline microstructure including a plurality of elongated crystallographic grains with grain boundaries, the iron-nitride material including at least one of an ??-Fe16N2 phase and a body-center-tetragonal (bct) phase comprising Fe and N. The disclosure is also directed a method producing an iron-nitride material.

Abstract: An example composition may include a plurality of grains including an iron nitride phase. The plurality of grains may have an average grain size between about 10 nm and about 200 nm. An example technique may include treating a composition including a plurality of grains including an iron-based phase to adjust an average grain size of the plurality of grains to between about 20 nm and about 100 nm. The example technique may include nitriding the plurality of grains to form or grow an iron nitride phase.

Abstract: Disclosed are energy efficient ferroelectric devices and methods for making such devices. For example, a ferroelectric device may be a ferroelectric tunneling junction device that includes a graphene layer on a substrate. A tunneling layer may be disposed on a portion of the graphene layer. The tunneling layer may be a ferroelectric material. A metal electrical contact layer may be disposed over the tunneling layer and the graphene layer. Additionally, some embodiments may have an additional monolayer disposed between the tunneling layer and graphene layer. By specific engineering of such layers, tunneling electroresistance performance may be substantially improved.

Abstract: Example nanoparticles may include an iron-based core, and a shell. The shell may include a non-magnetic, anti-ferromagnetic, or ferrimagnetic material. Example alloy compositions may include an iron-based grain, and a grain boundary. The grain boundary may include a non-magnetic, anti-ferromagnetic, or ferrimagnetic material. Example techniques for forming iron-based core-shell nanoparticles may include depositing a shell on an iron-based core. The depositing may include immersing the iron-based core in a salt composition for a predetermined period of time. The depositing may include milling the iron-based core with a salt composition for a predetermined period of time. Example techniques for treating a composition comprising core-shell nanoparticles may include nitriding the composition.

Abstract: A permanent magnet may include a Fe16N2 phase constitution. In some examples, the permanent magnet may be formed by a technique that includes straining an iron wire or sheet comprising at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal; nitridizing the iron wire or sheet to form a nitridized iron wire or sheet; annealing the nitridized iron wire or sheet to form a Fe16N2 phase constitution in at least a portion of the nitridized iron wire or sheet; and pressing the nitridized iron wires and sheets to form bulk permanent magnet.

Abstract: A permanent magnet may include a Fe16N2 phase constitution. In some examples, the permanent magnet may be formed by a technique that includes straining an iron wire or sheet comprising at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal; nitridizing the iron wire or sheet to form a nitridized iron wire or sheet; annealing the nitridized iron wire or sheet to form a Fe16N2 phase constitution in at least a portion of the nitridized iron wire or sheet; and pressing the nitridized iron wires and sheets to form bulk permanent magnet.

Abstract: A magnetic device includes a layer stack comprising a first ferromagnetic layer; a spacer layer on the first ferromagnetic layer; a second ferromagnetic layer on the spacer layer; a dielectric barrier layer on the second ferromagnetic layer; an insertion layer positioned between the second ferromagnetic layer and the dielectric barrier layer; and a fixed layer or an electrode on the dielectric barrier layer. In some examples, a magnetic orientation of the second ferromagnetic layer is switched by a bias voltage across the layer stack without application of an external magnetic field; an antiferromagnetic coupling of the first and second ferromagnetic layers is increased by the bias voltage applying a negative charge to the fixed layer or the electrode, and the antiferromagnetic coupling of the first and second ferromagnetic layers is decreased by the bias voltage applying a positive charge to the fixed layer or the electrode.

Abstract: A bioassay system includes at least one conductive excitation coil, the at least one conductive excitation coil configured to generate an alternating magnetic field including a first frequency and a second frequency. The bioassay system further includes a sample mount configured to position a sample within the at least one conductive excitation coil, and at least one sensing conductive coil configured to determine a magnetic response of a sample positioned within the sample mount to the alternating magnetic field.

Abstract: A stimulator includes a support layer, a coil supported by the support layer, the coil extending around a central area, and a plurality of pillars supported by the support layer in the central area.

Abstract: A neuro-stimulation system includes a stimulator controller, a support surface, and a magneto-ionic stimulator positioned on the support surface and electrically connected to the stimulator controller. The stimulator controller can apply a voltage to the magneto-ionic stimulator, wherein a change in the voltage causes a change in a magnetic field produced by the magneto-ionic stimulator.

Abstract: A permanent magnet may include a Fe16N2 phase in a strained state. In some examples, strain may be preserved within the permanent magnet by a technique that includes etching an iron nitride-containing workpiece including Fe16N2 to introduce texture, straining the workpiece, and annealing the workpiece. In some examples, strain may be preserved within the permanent magnet by a technique that includes applying at a first temperature a layer of material to an iron nitride-containing workpiece including Fe16N2, and bringing the layer of material and the iron nitride-containing workpiece to a second temperature, where the material has a different coefficient of thermal expansion than the iron nitride-containing workpiece. A permanent magnet including an Fe16N2 phase with preserved strain also is disclosed.

Abstract: Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one ??-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one ??-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Abstract: In some examples, a device includes a magnetic tunnel junction including a first Weyl semimetal layer, a second Weyl semimetal layer, and a dielectric layer positioned between the first and second Weyl semimetal layers. The magnetic tunnel junction may have a large tunnel magnetoresistance ratio, which may be greater than five hundred percent or even greater than one thousand percent.

Abstract: Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one ??-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one ??-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Abstract: A method may include wet ball milling a plurality of iron nitride nanoparticles in the presence of a surface active agent to modify a surface of the plurality of iron nitride nanoparticles and form a plurality of surface-modified iron nitride nanoparticles for a variety of biomedical applications and soft magnetic materials related applications.