314 results about "Antiferromagnetic coupling" patented technology

Magnetic tunnel junction (“MTJ”) element structures and methods for fabricating MTJ element structures are provided. An MTJ element structure may comprise a crystalline pinned layer, an amorphous fixed layer, and a coupling layer disposed between the crystalline pinned layer and the amorphous fixed layer. The amorphous fixed layer is antiferromagnetically coupled to the crystalline pinned layer. The MTJ element further comprises a free layer and a tunnel barrier layer disposed between the amorphous fixed layer and the free layer.Another MTJ element structure may comprise a pinned layer, a fixed layer and a non-magnetic coupling layer disposed therebetween. A tunnel barrier layer is disposed between the fixed layer and a free layer. An interface layer is disposed adjacent the tunnel barrier layer and a layer of amorphous material. The first interface layer comprises a material having a spin polarization that is higher than that of the amorphous material.

A basic design is disclosed for bottom shield (S1) and top shield (S2) of the reader shields in a magnetic read-write head. The critical part of new design includes an antiferromagnetic film which pins an antiferromagnetically coupled trilayer (AFCT). The simplest embodiment for top shield, for example, would be a film sequence of FM / Ru / FM / AFM. This replaces the normal top shield design which typically comprises a ferromagnetic seed layer and a thicker plated ferromagnetic film. Processes for manufacturing these shields are also described.

A memory cell (310) for a magnetic memory device (300) includes a free layer (311), a cap layer, an antiferromagnetic layer, and a synthetic antiferromagnetic layer which comprises two or more than two ferromagnetic layers that are antiferromagnetically coupled through non-magnetic space layers. The synthetic antiferromagnetic layer is pinned by antiferromagnetic layer. The antiferromagnetic layer and the synthetic antiferromagnetic layer form a synthetic antiferromagnetic pinned (SAFP) recording layer. The magnetization of the SAFP recording layer can be changed by combining a heating process and an external field induced from currents flowing along the bit line (320) and the word line (330). Therefore, a MRAM with high density, high thermal stability, low power dissipation and high heat tolerance can be achieved after introducing the SAFP recording layer due to the high volume and anisotropy energy of the SAFP recording layer.

An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate:(a) a continuous ferromagnetic stabilizing layer;(b) a non-magnetic spacer layer; and(c) a granular ferromagnetic recording layer;wherein:(i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing;(ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and(iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic spacer layer to thereby enhance thermal stability of the recording bits.

A current-in-plane magnetic sensor comprises a sensor stack including first and second layers of ferromagnetic material, a first nano-oxide layer positioned adjacent to the first layer of ferromagnetic material, and a layer of non-magnetic material positioned between the first and second layers of ferromagnetic material, wherein the thickness of the non-magnetic layer is selected to provide antiferromagnetic coupling between the first and second ferromagnetic layers, a magnetic field source for biasing the directions of magnetization of the first and second layers of ferromagnetic material in directions approximately 90° with respect to each other, a first lead connected to a first end of the sensor stack, and a second lead connected to a second end of the sensor stack. Disc drives that use the current-in-plane magnetic sensor are also included.

A method to switch a scalable magnetoresistive memory cell including the steps of providing a magnetoresistive memory device (12) having two bits (18) and (20) sandwiched between a word line (14) and a digit line (16) so that current waveforms (104) and (106) can be applied to the word and digit lines at various times to cause a magnetic field flux HW and HD to rotate the effective magnetic moment vectors (86) and (94) of the device (12) by approximately 180°. Each bit includes N ferromagnetic layers (32) and (34, 42) and (44, 60) and (62, 72 and 74) that are anti-ferromagnetically coupled. N can be adjusted to change the magnetic switching volume of the bit. One or both bits may be programmed by adjusting the current in the word and / or digit lines.

Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording / reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween. The device is provided with a means of keeping the magnetization direction of either one of the pair of ferromagnetic films constituting the pinned magnetic layer, and with a nonmagnetic high-conductivity layer as disposed adjacent to a first ferromagnetic layer on the side opposite to the side on which the first ferromagnetic layer is contacted with a nonmagnetic spacer layer. With that constitution, the device has extremely high sensitivity, and the bias point in the device is well controlled.

The magnetic device comprises a least two layers made of a magnetic material that are separated by at least one interlayer made of a non-magnetic material. The layers made of a magnetic material each have magnetization oriented substantially perpendicular to the plane of the layers. The layer of non-magnetic material induces an antiferromagnetic coupling field between the layers made of a magnetic material, the direction and amplitude of this field attenuating the effects of the ferromagnetic coupling field of magnetostatic origin that occurs between the magnetic layers.