127 results about "Ferromagnetic thin films" patented technology

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 method for depositing uniform and smooth ferromagnetic thin films with high deposition-induced microstructural anisotropy includes a magnetic material deposited in two or more static oblique deposition steps from opposed directions to form a free layer having a high kink Hk, a high energy barrier to thermal reversal, a low critical current in spin-torque switching embodiments, and improved resistance to diffusion of material from adjacent layers in the device. Nonmagnetic layers deposited by the static oblique deposition technique may be used as seed layers for a ferromagnetic free layer or to generate other types of anisotropy determined by the deposition-induced microstructural anisotropy. Additional magnetic or non-magnetic layers may be deposited by conventional methods adjacent to oblique layer to provide magnetic coupling control, reduction of surface roughness, and barriers to diffusion from additional adjacent layers in the device.

A ferromagnetic thin-film based magnetic field sensor with first and second sensitive direction sensing structures each having a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof having a magnetization reference layer on one and an anisotropic ferromagnetic material sensing layer on the other having a length in a selected length direction and a smaller width perpendicular thereto and parallel to the relatively fixed magnetization direction. The relatively fixed magnetization direction of said magnetization reference layer in each is oriented in substantially parallel to the substrate but substantially perpendicular to that of the other. An annealing process is used to form the desired magnetization directions.

A current determiner comprising a first input conductor and a first current sensor, formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween, and both supported on a substrate adjacent to and spaced apart from one another so they are electrically isolated with the first current sensor positioned in those magnetic fields arising from any input currents. A first shield/concentrator of a material exhibiting a substantial magnetic permeability is positioned between the substrate and the first input conductor. The substrate can include a monolithic integrated circuit structure containing electronic circuit components of which at least one is electrically connected to the first input conductor. A similar second current sensor can be individually formed, but can also be in the current determiner structure that is supported on the substrate along with a second input conductor supported on the substrate suited for conducting input currents therethrough. This second input conductor is positioned at that side of the second current sensor opposite to that side thereof facing the substrate so as to be adjacent to, yet spaced apart from, the second current sensor to thereby be electrically isolated from any direct circuit interconnection therewith on the substrate but to have the second current sensor positioned in those magnetic fields arising from the input currents in the second input conductor. In addition, a second shield/concentrator layer of material exhibiting a substantial magnetic permeability to serve as a magnetic field concentrator is positioned at that side of the second input conductor opposite to that side thereof facing the substrate. In the first instance, the second shield/concentrator layer is electrically connected to the second input conductor, and can be so connected in the second instance.

A ferromagnetic film according to the present invention includes ferromagnetic element and nonmagnetic element and has a first portion and a second portion. Concentration of the nonmagnetic element in the first portion is lower than an average concentration of the nonmagnetic element in the ferromagnetic film. On the other hand, concentration of the nonmagnetic element in the second portion is higher than the average concentration of the nonmagnetic element in the ferromagnetic film. The nonmagnetic element includes at least one element selected from the group consisting of Zr, Ti, Nb, Ta, Hf, Mo and W. The ferromagnetic film is applied to a magnetic free layer of a magneto-resistance element in an MRAM.

A ferromagnetic thin-film based magnetic field sensor having a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof upon one of which a magnetization reference layer is provided and upon the other there being provided a sensing layer. A spacer layer is provided on the sensing film to separate this sensing film from an augmenting film with the spacer layer being sufficiently thick so as to significantly reduce or eliminate topological coupling between the sensing and augmenting films, and to significantly randomize spin states of emerging electrons traversing therethrough.

A ferromagnetic thin-film based digital memory having a substrate supporting bit structures that are electrically interconnected with information storage and retrieval circuitry and having magnetic material films in which a characteristic magnetic property is substantially maintained below an associated critical temperature above which such magnetic property is not maintained separated by at least one layer of a nonmagnetic material with each bit structure having an interconnection structure providing electrical contact thereto at a contact surface thereof substantially parallel to the intermediate layer positioned between the first contact surface and the substrate. A plurality of word line structures located across from a corresponding one of the bit structures on an opposite side of the intermediate layer of a corresponding one of said bit structures from its interconnection structure provides electrical contact thereto. Sufficient electrical current selectively drawn through each of these bit structures and its interconnection structure can cause substantial heating of that bit structure to raise temperatures thereof to have at least one of the magnetic material films therein at least approach its corresponding associated critical temperature while being substantially above temperatures of at least an adjacent said bit structure because of sufficient thermal isolation.

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.

A ferromagnetic thin-film based magnetic device with internal film coupling compensation including a nonmagnetic material intermediate layer with an initial thin-film of an anisotropic ferromagnetic material on one side. A compensation thin-film of an anisotropic ferromagnetic material is provided on the opposite side with an antiparallel coupling layer thereon and a subsequent thin-film of an anisotropic ferromagnetic material on the antiparallel coupling layer with the compensation thin-film being less thick than the subsequent thin-film. A antiferromagnetic layer can be supported by the layers on either side of the intermediate layer.

The invention relates to a device and a method for detecting a force thermal magnetic coupling action of a ferromagnetic thin film, and belongs to the technical fields of engineering materials, structure deformation and mechanical experiments. The device comprises a ferromagnetic thin film uneven stress measuring optical circuit, a film magnetic hystersis loop measuring optical circuit, a Helmholtz coil and a power supply thereof, a test piece heating table, a thermocoupler, a force loading structure and an adjusting bracket. The film uneven stress measuring optical circuit comprises a laser, a beam expander, a spectroscope, a reflector, a raster, a lens, a filtering screen and a CCD camera; and the film magnetic hystersis loop measuring optical circuit comprises a laser, a beam expander, a reflector, a polarizer, a polarization analyzer and a photodetector. The method utilizes the Helmholtz coil to provide an even magnetic field for the ferromagnetic thin film, utilizes the test piece heating table to heat the film, utilizes the force loading structure to carry out force loading on the film, utilizes shearing interference to measure uneven curvature of the surface of the film and further obtain the stress of the film through the curvature, and utilizes Kerr magnetooptical effect on the surface of the ferromagnetic thin film to measure a magnetic hystersis loop of the film.

A monolithically formed ferromagnetic thin-film memory is disclosed that has local shielding on at least two sides of selected magnetic storage elements. The local shielding preferably extends along the back and side surfaces of a word line and/or digital lines of a conventional magnetic memory. In this configuration, the local shielding not only may help reduce externally generated EMI, internally generated cross-talk and other unwanted fields in the magnetic bit region, but may also help enhance the desired magnetic fields in the bit region.

A thin film magnet and a cylindrical ferromagnetic thin film having a high maximum energy product (greater than 120 kJ/m3) and thus suitable for use in miniature high performance devices are provided. The thin film magnet is produced by means of physical vapor deposition. The thin film magnet is an (Nd1-xRx)yM1-y-zBz alloy having a ferromagnetic compound of the Nd2Fe14B type as its main phase, wherein R is Tb, Ho, and Dy and M is Fe metal or an Fe-based alloy including at least one of Co and Ni, 0.04</=x</=0.10,0.11</=y</=0.15, and 0.08</=z</=0.15. A perpendicular magnetization film having such a composition is deposited on the side wall of a substrate in the columnar (or cylindrical) form thereby obtaining a cylindrical ferromagnetic thin film having radial anisotropy.

Spin transistors and related memory, memory systems, and methods are disclosed. A spin transistor is provided by at least two magnetic tunnel junctions (MTJs) with a shared multiferroic layer. The multiferroic layer is formed from a piezoelectric (PE) thin film over a ferromagnetic thin film (FM channel) with a metal electrode (metal). The ferromagnetic layer functions as the spin channel and the piezoelectric layer is used for transferring piezoelectric stress to control the spin state of the channel. The MTJ on one side of the shared layer forms a source and the MTJ on the other side is a drain for the spin transistor.

A ferromagnetic thin-film based digital memory having a bit structures therein a magnetic material film in which a magnetic property thereof is maintained below a critical temperature above which such magnetic property is not maintained, and may also have a plurality of word line structures each with heating sections located across from the magnetic material film in a corresponding one of the bit structures. These bit structures are sufficiently thermally isolated to allow selected currents in the adjacent word lines or in the bit structure, or both, to selectively heat the bit structure to approach the critical temperature. Such bit structures may have three magnetic material layers each with its own critical temperature for maintaining versus not maintaining a magnetic property thereof.

An online detection method for magnetoelasticity performance of thin-ferromagnetic-film, which belongs to the field of engineering materials, structure deformation, and mechanical test. The device implementing the method of the invention comprises a thin-ferromagnetic-film non-uniform stress measuring light path and a film hysteresis loop measuring light path, wherein, the film non-uniform stress measuring light path comprises a laser, a beam expander, a grating, a lens, a filter screen, and a CCD camera; and the film hysteresis loop measuring light path comprises a laser, a beam expander, a polarizer, an analyzer, and a photodetector. The method of the invention comprises the steps of measuring non-uniform curvature of the thin-ferromagnetic-film surface by shearing interferometer to obtain the non-uniform stress in film, and measuring the hysteresis loop of the film by using magnetooptic Kerr effect of the thin-ferromagnetic-film surface. The method can simultaneously online measure the non-uniform stress and the hysteresis loop of thin-ferromagnetic-film, so as to provide experimental basis for the research on magnetoelasticity coupling behavior of the thin-ferromagnetic-film.