Abstract: A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as to not be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is formed as a sandwich of two antiferromagnetically coupled ferromagnetic layers separated by a metallic layer. The free and pinned ferromagnetic layers are located in separate spaced-apart planes so as to not overlap the tunnel barrier layer.

Abstract: A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as to not be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is pinned by interfacial exchange coupling with an adjacent antiferromagnetic layer. The amount of tunneling current that flows perpendicularly through the two ferromagnetic layers and the intermediate tunnel barrier layer depends on the relative magnetization directions of the two ferromagnetic layers.

Abstract: A method for selectively etching insulative material composed of SrTiO3 or MgO in the presence of a copper oxide perovskite superconductive material includes treating the insulative material with a liquid selective etchant solution containing hydrogen fluoride in water for a period of time, the insulative material being etched at a substantially faster rate than the superconductive material etch rate, then treating the superconductive material exposed to the insulative selective with another etchant to remove a surface layer.

Abstract: A nonvolatile magnetic random access memory (MRAM) is an array of individual magnetic memory cells. Each memory cell is a magnetic tunnel junction (MTJ) element and a diode electrically connected in series. Each MTJ is formed of a pinned ferromagnetic layer whose magnetization direction is prevented from rotating, a free ferromagnetic layer whose magnetization direction is free to rotate between states of parallel and antiparallel to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier between and in contact with the two ferromagnetic layers. Each memory cell has a high resistance that is achieved in a very small surface area by controlling the thickness, and thus the electrical barrier height, of the tunnel barrier layer.

Abstract: A computing system is disclosed which operates using a digital computer which is programmed with a known programme, and information is fed into the computer from an input unit which incorporates a means to apply specific values for the initial conditions of selected variables and further means which are manually actuable to vary the value of the quantity representing a designated variable from its initial condition during computation in order that the response to such variation may be monitored on a display unit which conveniently is in the form of a video display unit. Additionally monitoring means in the form of lights which are operable in response to constraint violation may be included. The manually actuable means is disclosed in a form which is purely mechanical.