D.T. Huong Giang

Spatial angular positioning device with three-dimensional magnetoelectric sensors.

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 Earths 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 antennas orientation with respect to the position of the related geostationary satellite.

Enhancement of the Magnetic Flux in Metglas/PZT-Magnetoelectric Integrated 2D Geomagnetic Device

Experimental investigations of the magnetization, magnetostriction and magnetoelectric (ME) effects were performed on sandwich - type Metglas/PZT/Metglas laminate composites. The results have been analyzed by taking into account the demagnetization contribution. The study has pointed out that the magnetic flux concentration is strongly improved in piezomagnetic laminates with a narrower width leading to a significant enhancement of the ME effects. The piezomagnetic laminates with the optimal area dimension were integrated to form a 2-D geomagnetic device, which simultaneously can precisely detect the strength as well as inclination of the earth’s magnetic field. In this case, a magnetic field resolution of better than 10 �4 Oe and an angle precision of ± 0.1 o were determined. This simple and low-cost geomagnetic-field device is promising for various

Metglas/PZT-Magnetoelectric 2-D Geomagnetic Device for Computing Precise Angular Position

A magnetoelectric 2-D geomagnetic device for the precisely angular position computation is provided. The magnetic sensor module consists of two Metglas/PZT magnetoelectric 1-D sensors in an orthogonal arrangement. The sensor signals are excited and detected by a self-made digital lock-in amplifier. For mapping output sensor signals, normalization was performed on the operational module. Both spatial (azimuth and pitch) angles are then easily computed while rotating and/or swinging the sensor module. This simple and low-cost geomagnetic device is integrated with mobile transceivers for automatic determination and control of the latter antenna direction with respect to the position of the geostationary satellite in communication.

Combining large magnetostriction and large magnetostrictive susceptibility in TbFeCo∕YxFe1−x exchange-spring-type multilayers

An approach to obtain both large magnetostriction and large magnetostrictive susceptibility is developed. It is applied to sputtered {Tb(Fe0.55Co0.45)1.5∕(YxFe1−x)} (x=0, 0.1 and 0.2) multilayers. In the as-deposited samples, the TbFeCo layers are in the amorphous state, but the microstructure of the YxFe1−x layers is not the same: A crystalline state is observed in pure Fe layers (x=0), whereas body-centered-cubic-Fe nanocrystals coexist within an YFe amorphous matrix in Y0.1Fe0.9 layers. A parallel magnetostrictive susceptibility χλ‖ as large as 29.4×10−2T−1, which is almost half of that (79.6×10−2T−1) of the Metglas 2605SC was obtained for x=0.1. This is attributed to the exchange coupling between sandwiched TbFeCo layers and nanostructured YFe layers.