International Business Machines Corporation

Samsung Electronics Co., Ltd.

Stuart S P Parkin

Mahesh Govind Samant

Jaewoo Jeong

Yari Ferrante

Tze-Chiang Chen

Eric Andrew Joseph

Woojin Kim

Mary Beth Rothwell

Panagiotis Charilaos Filippou

Chirag Garg

Naga Phani B Aetukuri

Dharmendra S Modha

David William Abraham

Yong Jong Park

Philip Louis Trouilloud

Joonmyoung Lee

John Casimir Slonczewski

Keewon Kim

Sergey V Faleev

A device including a multi-layered structure that includes: a first layer that includes a first magnetic Heusler compound; a second layer that is non-magnetic at room temperature and includes both Ru and at least one other element E, wherein the composition of the second layer is represented by Ru1&#x2212;xEx, with x being in the range from 0.45 to 0.55; and a third layer including a second magnetic Heusler compound. The multi-layered structure may overlay a substrate. The device may include a tunnel barrier overlying the multi-layered structure.

Heusler compounds with non-magnetic spacer layer for formation of synthetic anti-ferromagnets (SAF)

A device is disclosed. The device includes a first magnetic layer and a tunnel barrier. The first magnetic layer has a volume uniaxial magnetic crystalline anisotropy. The magnetic moment of the first layer is substantially perpendicular to the first layer. The tunnel barrier is in proximity to the first magnetic layer. The orientation of the magnetic moment of the first magnetic layer is reversed by spin transfer torque induced by current passing between and through the first magnetic layer and the tunnel barrier.

Spin transfer torque switching of a magnetic layer with volume uniaxial magnetic crystalline anistotropy

Devices are described that include a multi-layered structure that comprises three layers. The first layer is a magnetic Heusler compound, the second layer (acting as a spacer layer) is non-magnetic at room temperature and comprises alternating layers of Ru and at least one other element E (preferably Al; or Ga or Al alloyed with Ga, Ge, Sn or combinations thereof), and the third layer is also a magnetic Heusler compound. The composition of the second layer is represented by RuE, with x being in the range from 0.45 to 0.55. An MRAM element may be constructed by forming, in turn, a substrate, the multi-layered structure, a tunnel barrier, and an additional magnetic layer (whose magnetic moment is switchable).

A device is disclosed. The device includes a tetragonal Heusler compound of the form MnCoGe, wherein 0&#x3c;x&#x2264;1, wherein Co accounts for at least 0.4 atomic percent of the Heusler compound. The device also includes a substrate oriented in the direction (001) and of the form YMn, wherein Y includes an element selected from the group consisting of Ir and Pt, and 0&#x2264;d&#x2264;4. The tetragonal Heusler compound and the substrate are in proximity with each other, thereby allowing spin-polarized current to pass from one through the other. In one aspect, the device also includes a multi-layered structure that is non-magnetic at room temperature. The structure includes alternating layers of Co and E. E includes at least one other element that includes Al. The composition of the structure is represented by CoE, with y being in the range from 0.45 to 0.55.

Tunable tetragonal ferrimagnetic heusler compound with PMA and high TMR

A device and method for providing the device are described. The device includes a substrate, a MnN layer overlying the substrate, a multi-layered structure that is non-magnetic at room temperature and a first magnetic layer. The MnN layer has 2&#x2264;x&#x2264;4.75. The multi-layered structure comprises alternating layers of Co and E, wherein E comprises at least one other element that includes Al. The composition of the multi-layered structure is represented by CoE, with x being in the range from 0.45 to 0.55. The first magnetic layer includes a Heusler compound. The first magnetic layer is in contact with the multi-layered structure and the first magnetic layer forms part of a magnetic tunnel junction.

Templating layers for forming highly textured thin films of heusler compounds switchable by application of spin transfer torque

Devices are described that include a multi-layered structure that is non-magnetic at room temperature, and which comprises alternating layers of Co and at least one other element E (that is preferably Al; or Al alloyed with Ga, Ge, Sn or combinations thereof). The composition of this structure is represented by CoE, with x being in the range from 0.45 to 0.55. The structure is in contact with a first magnetic layer that includes a Heusler compound. An MRAM element may be formed by overlying, in turn, the first magnetic layer with a tunnel barrier, and the tunnel barrier with a second magnetic layer (whose magnetic moment is switchable). Improved performance of the MRAM element may be obtained by placing an optional pinning layer between the first magnetic layer and the tunnel barrier.

Templating layers for perpendicularly magnetized Heusler films

An apparatus for separating oxygen from a gas mixture includes an oxide layer having ion transport channels therein, which facilitate the migration of oxygen ions from a first side to a second side of the layer. Molecular oxygen is decomposed into oxygen ions at the first side, whereas oxygen ions recombine into molecular oxygen at the second side. A first chamber into which a gas mixture (e.g., air) is admitted is located on the first side of the oxide layer. A second chamber receives oxygen from the oxide layer, and is located on the second side of the oxide layer; the second chamber has a polarizable medium that is in contact with the oxide layer. A gate electrode in contact with the polarizable medium applies an electric field to the second side of the oxide layer, thereby driving oxygen ions across the oxide layer.

Oxygen-separating device utilizing ionic oxygen motion

An apparatus includes an oxide layer having ion transport channels that facilitate the migration of oxygen ions from a first side to a second side of the layer. Specifically, molecular oxygen is decomposed into oxygen ions at the first side, and oxygen ions recombine into molecular oxygen at the second side. The apparatus includes a first chamber having a polarizable medium located on the second side of the oxide layer; a second chamber having an analyte that includes dissolved oxygen is located on the first side. The apparatus further includes a gate electrode that is in contact with, and applies a voltage to, the polarizable medium; in this manner, an electric field is applied to the second side of the oxide layer, which drives oxygen ions across the oxide layer. The apparatus can be used as an oxygen sensor, e.g., for detecting oxygen in a liquid such as blood.

Dissolved-oxygen sensor utilizing ionic oxygen motion

Devices are described that include a multi-layered structure that is non-magnetic at room temperature, and which comprises alternating layers of Co and at least one other element E (such as Ga, Ge, and Sn). The composition of this structure is represented by CoE, with x being in the range from 0.45 to 0.55. The structure is in contact with a first magnetic layer that includes a Heusler compound. An MRAM element may be formed by overlying, in turn, the first magnetic layer with a tunnel barrier, and the tunnel barrier with a second magnetic layer (whose magnetic moment is switchable). Improved performance of the MRAM element may be obtained by placing a pinning layer between the first magnetic layer and the tunnel barrier.

Templating layers for perpendicularly magnetized heusler films

Materials are disclosed that are used as seed layers in the formation of MRAM elements. In particular, a MnN layer oriented in the (001) direction is grown over a substrate. A magnetic layer overlying and in contact with the MnN layer forms part of a magnetic tunnel junction, in which the magnetic layer includes a Heusler compound that includes Mn. The magnetic tunnel junction includes the magnetic layer, a tunnel barrier overlying the magnetic layer, and a first (magnetic) electrode overlying the tunnel barrier. A second electrode is in contact with the MnN layer.

MnN and Heusler layers in magnetic tunnel junctions

A magnetic memory device includes a first magnetic structure on a substrate, a second magnetic structure between the substrate and the first magnetic structure, and a tunnel barrier between the first and second magnetic structures. At least one of the first and second magnetic structures includes a perpendicular magnetic layer on the tunnel barrier, and a polarization enhancement layer interposed between the tunnel barrier and the perpendicular magnetic layer. Here, the polarization enhancement layer contains cobalt, iron, and at least one of the elements of Group IV, and the polarization enhancement layer has a magnetization direction perpendicular to or substantially perpendicular to a top surface of the substrate.

Magnetic memory devices having perpendicular magnetic tunnel junction

Example embodiments relate to a magnetic memory device that includes a magnetic tunnel junction layer including a first magnetic layer, a second magnetic layer, and a first tunnel barrier layer between the first and second magnetic layers. The second magnetic layer is disposed on the first tunnel barrier layer and is in direct contact with the first tunnel barrier layer. The second magnetic layer includes cobalt-iron-beryllium (CoFeBe). A beryllium content of CoFeBe in the second magnetic layer ranges from about 2 at % to about 10 at %.

Magnetic memory device and method for manufacturing the same

A layered stack includes a first layer having a first spin polarization and a first magnetic moment, as well as a second layer (in contact with the first layer) having a second spin polarization a second magnetic moment. The first and second spin polarizations have the same orientation, but the first and second magnetic moments have orientations that partially cancel each other, thereby recommending the layered stack for applications in magnetic tunnel junctions, for example.

Termination layer-compensated tunneling magnetoresistance in ferrimagnetic Heusler compounds with high perpendicular magnetic anisotropy

A structure includes a tetragonal Heusler of the form MnX, in which X includes an element selected from the group consisting of Ge and Ga, with 0&#x2266;c&#x2266;3. The tetragonal Heusler is grown directly on (or more generally, over) a substrate oriented in the direction (001) and of the form YMn, wherein Y includes an element selected from the group consisting of Ir and Pt, with 0&#x2266;d&#x2266;4. The tetragonal Heusler and the substrate are in proximity with each other, thereby allowing spin-polarized current to pass from one through the other. This structure may form part of a magnetic tunnel junction magnetoresistive device, and an array of such magnetoresistive devices may together form an MRAM.

Underlayers for textured films of Heusler compounds

A method for forming a memory device includes forming a cavity having an inner surface with an undulating profile in a substrate, depositing a ferromagnetic material in the cavity, forming a reading element on the substrate proximate to a portion of the ferromagnetic material, and forming a writing element on the substrate proximate to a second portion of the ferromagnetic material.

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San Jose, CA, United States of America

Stuart S P Parkin