Abstract: Passive solid-state magnetic sensors comprise a magnetostrictive material in contact with a piezoelectric material. The magnetostrictive material strains under the influence of an external magnetic field and imparts stress to the piezoelectric material to produce a detectable voltage signal indicative of the external field. Sensors have applications in rotor speed detection, electrical current measurements, magnetic imaging, magnetic field detection, read heads, and MRAM, for example.

Abstract: Passive solid-state magnetic sensors are based on the combination of magnetorestrictive materials and piezoelectric materials. Sensors have applications in rotor speed detection, magnetic field detection, read heads, and MRAM, for example.

Abstract: Methods and systems for estimating a value of a static or time varying magnetic field that is present. In a first embodiment, a layer of a magnetostrictive (MNS) material and a layer of a piezoresistive (PZR) material are combined and exposed to the unknown magnetic field, and a current source and charge-carrying line are connected between two spaced apart locations in the PZR layer. A meter measures a voltage difference or current between the two locations and estimates the value of the magnetic field. In a second embodiment, a layer of a magnetostrictive (MNS) material and a layer of a piezoelectric (PZT) material are combined and exposed to a combination of the unknown magnetic field and a selected time varying magnetic field. A meter measures a voltage change, current change or other electrical variable between two spaced apart locations at two or more selected times and estimates the value of the unknown magnetic field.

Abstract: Passive solid-state magnetic sensors are based on the combination of magnetorestrictive materials and piezoelectric materials. Sensors have applications in motor speed detection, magnetic field detection, read heads, and MRAM, for example.

Abstract: Method and system for estimating a concentration of free electrons with a selected spin polarization in a semiconductor material. A static magnetic field and an electromagnetic field are impressed on the semiconductor, and free electrons are injected (through diffusion or tunneling) into the semiconductor material from a ferromagnetic material. Motion of the injected, spin-polarized electrons, within the semiconductor gives rise to a Hall voltage across the semiconductor. This voltage is measured at one or more spaced apart locations and analyzed to detect presence of, and estimate a concentration of, free electrons with a selected spin at at least one location within the semiconductor. Effects of an imposed stress, temperature, illumination or electromagnetic field on the semiconductor can be determined.

Abstract: Passive solid-state magnetic sensors are based on the combination of magnetorestrictive materials and piezoelectric materials. Sensors have applications in rotor speed detection, magnetic field detection, read heads, and MRAM, for example.