Various embodiments include an electrical device comprising an antiferromagnetic topological insulator having a surface comprising a bulk domain wall configured to support a first type of 1D chiral channel, a surface step configured to support a second 1D chiral channel and intersecting the bulk domain wall to form thereat a quantum point junction.

A permanent magnet includes a stack of N patterns stacked immediately one above the other in a stacking direction, each pattern including an antiferromagnetic layer made of antiferromagnetic material, a ferromagnetic layer made of ferromagnetic material, the directions of magnetization of the various ferromagnetic layers of all the patterns all being identical to one another. At least one ferromagnetic layer includes a first sub-layer made of CoFeB whose thickness is greater than 0.05 nm, and a second sub-layer made of a ferromagnetic material different from CoFeB and whose thickness is greater than the thickness of the first sub-layer.

This invention relates to structures comprising magnetic materials and conjugated molecules. The invention relates to magneto-resistive devices based on such structures. Structures and devices of the invention can be used as magnetic switches, magnetic sensors and in devices such in/as memory devices.

A magnetoelectric composition of boron and chromia is provided. The boron and chromia alloy can contain boron doping of 1%-10% in place of the oxygen in the chromia. The boron-doped chromia exhibits an increased critical temperature while maintaining magnetoelectric characteristics. The composition can be fabricated by depositing chromia in the presence of borane. The boron substitutes oxygen in the chromia, enhancing the exchange energy and thereby increasing Néel temperature.

A composition of matter consisting primarily of a stabilizing element and a transition metal oxide, wherein the transition metal oxide is an anti-ferromagnetic Mott insulator with strong spin orbit interactions, and the composition of matter has a canted crystal structure.

A hall bar device for a memory or logic application can include a gate electrode, a boron-doped chromia layer on the gate electrode; and a hall bar structure with four legs on the boron-doped chromia layer. For a memory application, the hall bar device can be written to by applying a pulse voltage across the gate electrode and one leg of the hall bar structure in the absence of an applied magnetic field; and can be read from by measuring a voltage across the one leg of the hall bar structure and its opposite leg.

A hall bar device for a memory or logic application can include a gate electrode, a boron-doped chromia layer on the gate electrode; and a hall bar structure with four legs on the boron-doped chromia layer. For a memory application, the hall bar device can be written to by applying a pulse voltage across the gate electrode and one leg of the hall bar structure in the absence of an applied magnetic field; and can be read from by measuring a voltage across the one leg of the hall bar structure and its opposite leg.

Also disclosed herein is an article having a substrate and a layer of an FeRh alloy disposed on the substrate. The alloy has a continuous antiferromagnetic phase and one or more discrete phases smaller in area than the continuous phase having a lower metamagnetic transition temperature than the continuous phase. Also disclosed herein is a method of: providing an article having a substrate and a layer having a continuous phase of an antiferromagnetic FeRh alloy disposed on the substrate and directing an ion source at one or more portions of the alloy to create one or more discrete phases having a lower metamagnetic transition temperature than the continuous phase.

A magnetic device can include a substrate layer and an Fe.sub.1-xRh.sub.x film on the substrate layer, where x is in a range from about 0.47 to about 0.50, wherein a local region in the Fe.sub.1-xRh.sub.x film has a bistable magnetic order at a temperature between about 275K and about 325K. Films of Iron and Rhodium (FeRh) can provide both ferromagnetic (FM) and antiferromagnetic (AF) orders which are metastable at room temperature. For example, the composition of the Fe.sub.1-xRh.sub.x film can be controlled such that 0.47<x<0.50 so that after the magnetic order of the film (or a local region of the film) is established as AF or FM, the magnetic order can remain undisturbed while the temperature of the film varies within a range of room temperature.

Spintronic devices based on metallic antiferromagnets having a non-collinear spin structure are provided. Also provided are methods for operating the devices. The spintronic devices are based on a bilayer structure that includes a spin torque layer of an antiferromagnetic material having a non-collinear triangular spin structure adjoining a layer of ferromagnetic material.