This paper reports on the development of a novel simple three-dimensional geomagnetic device for sensing the spatial azimuth and pitch positions by using three one-dimensional magnetoelectric sensors assembled along three orthogonal axes. This sensing device combines piezoelectric transducer plates and elongated high-performance Ni-based Metglas ribbons. It allows the simultaneous detection of all three orthogonal components of the terrestrial magnetic field. Output signals from the device components are provided in form of sine and/or cosine functions of both the rotation azimuth and the pitch angles, from which the total intensity as well as the inclination angle of the Earth's magnetic field is determined in an overall field resolution of better than 10−4 Oe and an angle precision of ±0.1°, respectively. This simple and low-cost geomagnetic-field device is promising for the automatic determination and control of the mobile transceiver antenna's orientation with respect to the position of the related geostationary satellite.
29 November 2018 in Journal of Electronic Materials
Distance magnetic nanoparticle detections were investigated by using a magnetoelectric based magnetic sensor with a long type bilayer Metglas/PZT laminate composite. In homogeneous magnetic fields, the sensor exhibits a sensitivity of 307.4 mV/Oe, which is possible for a detection limit of 2.7 × 10−7 emu. This sensor can detect an amount of 0.31 μg of the superparamagnetic Fe3O4-chitosan fluid at 2 mm height above the sensor surface. To detect a spot with magnetic nanoparticles at a distance of about 7.6 mm, it should contain at least 50 μg of iron oxide. This approach can develop the local detection of magnetic nanoparticles at a depth of centimeters in the body during clinical interventions.
8 May 2013 in Advances in Natural Sciences: Nanoscience and Nanotechnology
Electric-field modulating exchange bias and near 180° deterministic magnetization switching at room temperature are demonstrated in simple antiferromagnetic/ferromagnetic/ferroelectric (AFM/FM/FE) exchange-coupled multiferroic multilayers of IrMn/Co/PZT. A rather large exchange bias field shift up to ΔHex/Hex = 500% was obtained. This change governs mainly the electric-field strength rather than the applied current. It is explained as being realized through the competition between the electric-field induced uniaxial and unidirectional anisotropies. These results show good prospects for low-power spintronic devices.
This paper describes the route, from simulations toward experiments, for optimizing the magnetoelectric (ME) geometries for vortex magnetic field sensors. The research is performed on the base of the Metglas/Piezoelectric (PZT) laminates in both open and closed magnetic circuit (OMC and CMC) geometries with different widths (W), lengths (L), and diameters (D). Among these geometries, the CMC laminates demonstrate advantages not only in their magnetic flux distribution, but also in their sensitivity and in their independence of the position of the vortex center. In addition, the ME voltage signal is found to be enhanced by increasing the magnetostrictive volume fraction. Optimal issues are incorporated to realize a CMC-based ME double sandwich current sensor in the ring shape with D × W = 6 mm × 1.5 mm and four layers of Metglas. At the resonant frequency of 174.4 kHz, this sensor exhibits the record sensitivity of 5.426 V/A as compared to variety of devices such as the CMC ME sensor family, fluxgate, magnetoresistive, and Hall-effect-based devices. It opens a potential to commercialize a new generation of ME-based current and (or) vortex magnetic sensors.
1 June 2016 in Journal of Science: Advanced Materials and Devices
String based MEMS devices recently attract world technology development thanks to their advantages over cantilever ones. Approaching to this direction, the paper reports on the micro-fabrication and characterization of free-standing doubly clamped piezoelectric beams based on heterostructures of Pd/FeNi/Pd/PZT/LSMO/STO/Si. The displacement of strings is investigated in both static and dynamic mode. The static response exhibits a bending displacement as large as 1.2 μm, whereas the dynamic response shows a strong resonance with a high quality factor of around 35 depending on the resonant mode at atmospheric pressure. These findings are comparable with those observed in large dimension membrane and cantilever based MEMS devices, which exhibit high potentials in variety of sensor and resonant actuator applications