Abstract: A radio-frequency oscillator incorporates a magnetoresistive device within which an electron current is able to flow. The device includes a stack including: a magnetic trapped layer, the magnetization of which is of substantially fixed direction; a magnetic free layer; and a non-magnetic intermediate layer-interposed between the free layer and the trapped layer. The oscillator also includes a mechanism capable of making an electron current flow in the layers constituting the stack and in a direction perpendicular to the plane which contains the layers. At least the free layer is devoid of any material at its center. The electron current density flowing through the stack is capable of generating a magnetization in the free layer in a micromagnetic configuration in the shape of a skewed vortex flowing in the free layer around the center of the free layer.

Abstract: The invention relates to a radiofrequency oscillator which incorporates: a spin-polarized electric current magnetoresistive device (6) for generating an oscillating signal at an oscillation frequency on an output terminal (10), and a terminal (18) for controlling the frequency or amplitude of the oscillating signal, and a feedback loop (44) comprising an amplifier (46) provided with: an input connected to the output terminal (10) of the magnetoresistive device (6) so as to amplify the portion of an oscillating signal detected at the output terminal, and an output connected to the control terminal (18) so as to inject onto said control terminal the amplified portion of the oscillating signal which is phase-related to the oscillating signal generated at the output terminal.

Abstract: The invention relates to a radio frequency oscillator which incorporates: a spin-polarized electric current magnetoresistive device (6), a terminal (18) for controlling the frequency or amplitude of the oscillating signal, a servo loop (34) connected between the output terminal and the control terminal for applying a control signal to the control terminal in order to slave a characteristic of the oscillating signal to a reference value, the servo loop (34) comprising: a sensor (36) of the amplitude of the oscillating signal oscillations, and a comparator (38) capable of generating the control signal according to the measured amplitude and the reference value.

Abstract: A radiofrequency oscillator comprises: a free layer (4), a current injector (6) for injecting spin-polarized current into the free layer, this injector having a spin-polarized current injection face (16) directly in contact with the free layer, a magnetoresistive contact (8) having a measurement face (26) directly in contact with the free layer, in order to form, in combination with the free layer, a tunnel junction for measuring the precession of the magnetization of the free layer, a conducting pad (30) directly in contact with the free layer in order to make an electrical current flow through the injector without passing through the magnetoresistive contact. At least part of the measurement face (26) and part of the injection face (16) are placed facing each other on each side of the free layer (4).

Abstract: An oscillation detector having an RF oscillator configured to be synchronized with a first frequency and a comparator for distinguishing the synchronized state from the non-synchronized state of the radiofrequency oscillator on the basis of an oscillating signal produced by the radiofrequency oscillator and indicating the presence of oscillations in a frequency band around the first frequency in response to identifying the synchronized state and, in alternation, indicating the absence of oscillations in this frequency band otherwise.

Abstract: A demodulator of an FM signal modulated about a carrier frequency with a modulation frequency has an RF oscillator configured to be synchronized, under identical conditions of operation, with oscillations at first and second frequencies used in the FM signal to encode respective pieces of information. The oscillator has a magnetoresistive device; and a low-pass filter connected to an output electrode of the magnetoresistive device to filter an oscillating signal, generated by the oscillator and to a rendering terminal to provide, as a demodulated electrical signal, the filtered signal, the cut-off frequency fc at ?3 dB of this filter being strictly lower than the frequency and higher than the modulation frequency.

Abstract: This magnetic device integrates a magneto-resistive stack, the stack comprising at least two layers made out of a ferromagnetic material, separated from each other by a layer of non-magnetic material; and means for causing an electron current to flow perpendicular to the plane of the layers, with at least one integrated nano-contact intended to inject the current into the magneto-resistive stack. The nano-contact is made in a bilayer composed of a solid electrolyte on which has been deposited a soluble electrode composed of a metal that has been at least partially dissolved in the electrolyte.

Abstract: A radio-frequency oscillator incorporates a magnetoresistive device within which an electron current is able to flow. The device includes a stack including: a magnetic trapped layer, the magnetization of which is of substantially fixed direction; a magnetic free layer; and a non-magnetic intermediate layer-interposed between the free layer and the trapped layer. The oscillator also includes a mechanism capable of making an electron current flow in the layers constituting the stack and in a direction perpendicular to the plane which contains the layers. At least the free layer is devoid of any material at its center. The electron current density flowing through the stack is capable of generating a magnetization in the free layer in a micromagnetic configuration in the shape of a skewed vortex flowing in the free layer around the center of the free layer.

Abstract: This radio-frequency oscillator includes a magnetoresistive device in which an electric current is able to flow. The magnetoresistive device includes a first magnetic layer, known as a “trapped layer”, whereof the magnetization is of fixed direction. The magnetoresistive device further includes a second magnetic layer known as a “free layer” and a non-magnetic layer, known as an “intermediate layer”, interposed between the first and second layer, known as the intermediate layer. The oscillator further includes means capable of causing an electron current to flow in said layers constituting the aforementioned stack and in a direction perpendicular to the plane which contains said layers. One of the three layers constituting the magnetoresistive device includes at least one constriction zone of the electric current passing through it.

Abstract: According to this method for producing a magnetic tunnel junction, a film of a dielectric material capable of acting as a tunnel barrier is deposited between two nanocrystalline or amorphous magnetic films. The dielectric material constituting the tunnel barrier consists of an at least partially crystalline perovskite, and said material is deposited by ion beam sputtering in a vacuum chamber.

Abstract: A method for constructing a magnetoresistive sensor using an etch mask that is resistant to the material removal process used to define the sensor width and stripe height. The method may include the use of a Ta etch mask formed under a photoresist mask, and the use of an ion milling process to define the sensor. The etch mask remains substantially intact after performing the ion milling and therefore is readily removed by a later CMP process. The etch mask layer is also very resistant to high temperatures such as those used in a desired atomic layer deposition of alumina, which is used to deposit conformal layers of alumina around the sensor.

Abstract: This radio-frequency oscillator includes a magnetoresistive device in which an electric current is able to flow. The magnetoresistive device includes a first magnetic layer, known as a “trapped layer”, whereof the magnetization is of fixed direction. The magnetoresistive device further includes a second magnetic layer known as a “free layer” and a non-magnetic layer, known as an “intermediate layer”, interposed between the first and second layer, known as the intermediate layer. The oscillator further includes means capable of causing an electron current to flow in said layers constituting the aforementioned stack and in a direction perpendicular to the plane which contains said layers. One of the three layers constituting the magnetoresistive device includes at least one constriction zone of the electric current passing through it.

Abstract: This magnetic device integrates a magneto-resistive stack, the stack comprising at least two layers made out of a ferromagnetic material, separated from each other by a layer of non-magnetic material; and means for causing an electron current to flow perpendicular to the plane of the layers, with at least one integrated nano-contact intended to inject the current into the magneto-resistive stack. The nano-contact is made in a bilayer composed of a solid electrolyte on which has been deposited a soluble electrode composed of a metal, and at least partially dissolved in the electrolyte.

Abstract: A method is disclosed for fabricating a read head for a magnetic disk drive having a read head sensor and a hard bias layer, where the read head has a shaped junction between the read head sensor and the hard bias layer. The method includes providing a layered wafer stack to be shaped. A single- or multi-layered photoresist mask having no undercut is deposited upon the layered wafer stack to be shaped. The layered wafer stack is shaped by the output of a milling source, where the shaping includes partial milling to within a partial milling range to form a shaped junction. A hard bias layer is then deposited which is in contact with the shaped junction of the wafer stack.

Abstract: A method for fabricating magnetic side shields for an MR sensor of a magnetic head. Following the deposition of MR sensor layers, a first DLC layer is deposited. Milling mask layers are then deposited, and outer portions of the milling mask layers are removed such that a remaining central portion of the milling mask layers is formed having straight sidewalls and no undercuts. Outer portions of the sensor layers are then removed such that a relatively thick remaining central portion of the milling mask resides above the remaining sensor layers. A thin electrical insulation layer is deposited, followed by the deposition of magnetic side shields. A second DLC layer is deposited and the remaining mask layers are then removed utilizing a chemical mechanical polishing (CMP) liftoff step. Thereafter, the first DLC layer and the second DLC layer are removed and a second magnetic shield layer is then fabricated thereabove.

Abstract: This method for making a nano-contact on a spin valve for the purposes of constituting a radio-frequency oscillator, consists, after deposition of the magnetic stack constituting the spin valve on a lower electrode in depositing on said magnetic stack a metal layer known as a “barrier” layer; in depositing on this “barrier” layer another metal layer; in depositing locally on this metal layer a hard mask; in subjecting the assembly to a first selective etching step of the metal layer constituting the injector through the hard mask, said metal layer being over-etched during this step under the hard mask in order to give the nano-contact its final dimension; in subjecting the assembly so obtained to a second selective etching step, able to induce the partial removal of the barrier layer and of the magnetic stack substantially on the periphery of the hard mask; in encapsulating the assembly obtained in a dielectric; in planarizing the encapsulated assembly so obtained until ending plumb with the residual layer of

Abstract: A method for fabricating a read head sensor for a magnetic disk drive is presented. The method includes providing a layered wafer stack to be shaped, where the layered wafer stack includes a free layer, a barrier layer and a pinned layer. A single- or multi-layered photoresist mask is formed upon the layered wafer stack to be shaped. A material removal source is provided and used to perform a partial depth material removal within a partial depth material removal range which extends from the free layer to within the pinned layer to a partial depth material removal endpoint. In various embodiments, this depth endpoint lies at or within the barrier layer or within but not through the pinned layer.

Abstract: A read head and a magnetic hard disk drive having a read head layer stack which has been partially milled to within a partial milling range to form a shaped junction and a hard bias layer which is in contact with the shaped junction of the wafer stack.

Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer having tab areas on opposite sides of an active area, forming a first layer of a carbon composition above the active area of the free layer, the first layer of carbon being substantially absent from tab areas of the free area, forming spacer layers above the tab areas of the free layer, the spacer layers being operable to make magnetic moments of ferromagnetic layers on opposite sides thereof antiparallel, forming bias layers above the spacer layers, the bias layers being operative to substantially pin magnetic moments of the tab areas of the free layer, forming second layers of carbon composition above the tab areas of the free layer, and removing the layers of carbon composition and any portions of the layers overlying the layers of carbon composition.

Abstract: A method for fabricating a read head for a magnetic disk drive having a read head sensor and a hard bias layer, where the read head has a shaped junction between the read head sensor and the hard bias layer. The method includes providing a layered wafer stack to be shaped. A single- or multi-layered photoresist mask having no undercut is deposited upon the layered wafer stack to be shaped. The layered wafer stack is shaped by the output of a milling source, where the shaping includes partial milling to within a partial milling range to form a shaped junction. A hard bias layer is then deposited which is in contact with the shaped junction of the wafer stack.