A device includes a seed layer, a magnetic track layer disposed on the seed layer, an alloy layer disposed on the magnetic track layer, a tunnel barrier layer disposed on the alloy layer, a pinning layer disposed on the tunnel barrier layer, a synthetic antiferromagnetic layer spacer disposed on the pinning layer, a pinned layer disposed on the synthetic antiferromagnetic spacer layer and an antiferromagnetic layer disposed on the pinned layer, and another device includes a seed layer, an antiferromagnetic layer disposed on the seed layer, a pinned layer disposed on the antiferromagnetic layer, a synthetic antiferromagnetic layer spacer disposed on the pinned layer, a pinning layer disposed on the synthetic antiferromagnetic layer spacer, a tunnel barrier layer disposed on the pinning layer, an alloy layer disposed on the tunnel barrier layer and a magnetic track layer disposed on alloy layer.

An improved magnetic tunnel junction with two oxide interfaces on each side of a ferromagnetic layer (FML) leads to higher PMA in the FML. The novel stack structure allows improved control during oxidation of the top oxide layer. This is achieved by the use of a FML with a multiplicity of ferromagnetic sub-layers deposited in alternating sequence with one or more non-magnetic layers. The use of non-magnetic layers each with a thickness of 0.5 to 10 Angstroms and with a high resputtering rate provides a smoother FML top surface, inhibits crystallization of the FML sub-layers, and reacts with oxygen to prevent detrimental oxidation of the adjoining ferromagnetic sub-layers. The FML can function as a free or reference layer in an MTJ. In an alternative embodiment, the non-magnetic material such as Mg, Al, Si, Ca, Sr, Ba, and B is embedded by co-deposition or doped in the FML layer.

A free layer has a switchable magnetization direction. A reference layer has a fixed magnetization direction. A barrier layer is provided between the free layer and the reference layer. The free layer includes a perpendicularity-maintaining layer and a high-polarizability magnetic layer. The perpendicularity-maintaining layer, if in contact with the barrier layer, has a first surface roughness. The high-polarizability magnetic layer, if in contact with the barrier layer, has a second surface roughness. If the first surface roughness is smaller than the second surface roughness, the perpendicularity-maintaining layer is in contact with the barrier layer. If the second surface roughness is smaller than the first surface roughness, the high-polarizability magnetic layer is in contact with the barrier layer.

Provided herein are systems, methods, and compositions for magnetic nanoparticles and bulk nanocomposite magnets.

The purpose of the present invention is to provide a magnetic recording medium capable of achieving high recording density by decreasing the bit transition width of a heat-assisted magnetic recording medium during the heat-assisted recording stage. The magnetic recording medium according to the present invention includes a non-magnetic substrate and a magnetic recording layer, wherein the magnetic recording layer includes an ordered alloy containing Fe, Pt and Ru, the ordered alloy includes x atom % of Fe, y atom % of Pt and z atom % of Ru on the basis of the total number of the Fe, Pt and Ru atoms, and the parameters x, y and z satisfy the following expressions (i)-(v): (i) 0.85x/y1.3; (ii) x53; (iii) y51; (iv) 0.6z20; and (v) x+y+z=100.

Various embodiments to mitigate the contamination of electroplated cobalt-platinum films on substrates are described. In one embodiment, a device includes a substrate, a titanium nitride diffusion barrier layer formed upon the substrate, a titanium layer formed upon the titanium nitride diffusion barrier layer, a platinum seed layer, and a cobalt-platinum magnetic layer formed upon the platinum seed layer. Based in part on the use of the titanium nitride diffusion barrier layer and/or the platinum seed layer, improvements in the interfaces between the layers can be achieved after annealing, with less delamination, and with substantial improvements in the magnetic properties of the cobalt-platinum magnetic layer. Further, the cobalt-platinum magnetic layer can be formed at a relatively thin thickness of hundreds of nanometers to a few microns while still maintaining good magnetic properties.

The present invention relates to a cobalt (Co) and platinum (Pt)-based multilayer thin film having a novel structure and perpendicular magnetic anisotropy, and to a fabrication method thereof. More specifically, the invention relates to a cobalt and platinum-based multilayer thin film having perpendicular magnetic anisotropy (PMA), which includes thin cobalt layers and thin platinum layers alternately deposited over a substrate, and has an inverted structure in which a thickness of the thin cobalt layers is greater than that of the thin platinum layers, and to a fabrication method thereof. The cobalt and platinum-based multilayer thin film has a new structure in which the thickness of a magnetic thin layer is greater than that of a non-magnetic thin layer. The multilayer thin film may be easily applied as a free layer and a pinned layer in a magnetic tunnel junction by controlling the perpendicular magnetic anisotropy energy depending on the thickness ratio of the layers. Also, the multilayer thin film has excellent thermal stability, and thus maintains its PMA energy density even after being subjected to a heat treatment process. In addition, it enables a fine amount of in-plane magnetic anisotropy to be formed by heat treatment so as to reduce the critical current density required for magnetization switching. Therefore, it may be advantageously used for high-performance and high-density MRAM.

Provided herein are systems, methods, and compositions for magnetic nanoparticles and bulk nanocomposite magnets.

A spin transfer torque magnetic junction includes a magnetic reference layer structure with magnetic anisotropy perpendicular to a substrate plane. A laminated magnetic free layer comprises at least three sublayers (e.g. sub-layers of CoFeB, CoPt, FePt, or CoPd) having magnetic anisotropy perpendicular to the substrate plane. Each such sublayer is separated from an adjacent one by a dusting layer (e.g. tantalum). An insulative barrier layer (e.g. MgO) is disposed between the laminated free layer and the magnetic reference layer structure. The spin transfer torque magnetic junction includes conductive base and top electrodes, and a current polarizing structure that has magnetic anisotropy parallel to the substrate plane. In certain embodiments, the current polarizing structure may also include a non-magnetic spacer layer (e.g. MgO, copper, etc).

Disclosed are a spin-orbit torque material and device, and use of a delafossite oxide thin film, which relate to the field of spintronics. A chemical formula of the spin-orbit torque material is ABO.sub.2; wherein A and B are different heavy metal atoms, O is an oxygen atom, and a ratio between the numbers of A, B, and O atoms is 1:1:2. The spin-orbit torque material of an embodiment of the present application has higher spin-orbit torque efficiency and lower resistivity, and can reduce the power consumption of a spin-orbit torque device when it is used in the device.