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This paper aims to investigate the influence of structure parameters on giant-magnetoimpedance (GMI) effect measured by non-contact method.

The GMI sensor contains a Co-based internal magnetic core fabricated by laser cutting and an external solenoid. The influences of magnetic permeability of magnetic core and structure parameters on GMI effect were calculated in theoretical model. The output impedance, resistance, reactance and GMI ratio were measured by non-contact method using impedance analyzer.

Enhancing external magnetic field intensity can decrease the magnetic permeability of core, which has vital influences on the magnetic property and the output response of GMI sensor. In addition, increasing the width of magnetic core and the number of solenoid turns can increase the maximum GMI ratio. The maximum GMI ratio is 3,230% with core width of 6 mm and solenoid turns of 200.

Comparing with traditional contact-measured GMI sensor, the maximum GMI ratio and the magnetic field sensitivity are improved and the power consumption is decreased in non-contact measured GMI sensor. GMI sensor measured by non-contact method has a wide range of potential applications in ultra-sensitive magnetic field detection.

This paper aims to investigate magnetic field anneal in micro-patterned Co-based amorphous ribbon on giant magneto-impedance (GMI) effect enhancement.

The amorphous ribbons were annealed in transverse and longitudinal magnetic field. The influence of different field annealing directions on GMI effect and impedance Z, resistance R and reactance X with a series of line width have been deeply analyzed.

In comparison with GMI sensors microfabricated by unannealed and transversal field annealed ribbons, GMI sensor which was designed and microfabricated by longitudinal field anneal ribbon performs better. The results can be explained by the domain wall motion and domain rotation during annealing process and the geometric structure of Co-based GMI sensor. In addition, shrinking the line width of GMI sensor can promote GMI effect significantly because of the effect of demagnetizing field, and the optimum GMI ratio is 209.7 per cent in longitudinal field annealed GMI sensor with 200 μm line width.

In conclusion, annealing in longitudinal magnetic field and decreasing line width can enhance GMI effect in micro-patterned Co-based amorphous ribbon.

The paper aims to present a device devoted to detect and measure earth displacements produced by landslides. This device is an inclinometer type geotechnical instrument. It is widely known that landslides are categorized among the most destructive disasters that yearly produce huge damages and even human lives losses.

The principle of operation is based on measuring the deformation produced during soil layers sliding to a rod vertically mounted into the ground. The rod deformation is detected by highly sensitive strain gauges developed by authors using the stress impedance effect occurring in non-magnetostrictive magnetic amorphous microwires. The gauges are mounted in bridge configurations along the rod, beside the corresponding analogue and digital signal processing circuitry.

The landslide transducer is able to calculate the displacement of the soil layers at different levels of depth and the direction of the landslide. It has been tested in laboratory in terms of sensitivity and accuracy. A resolution of less than 1 mm has been achieved for displacement detection, whereas orientation may be calculated with about a maximum accuracy of less than 20 degrees.

Problems occurred in the manufacturing process of the gauges because of the quite large dispersion of the microwire parameters, as well as with gluing the gauges on the rod, that is compulsory to be well done, otherwise the gauges relaxation occurs with consequence in time stability decay.

With respect to other commercial devices, our inclinometer is characterized by high sensitivity and also by possibility of 3D measuring, it being able to gauge in depth the amplitude and orientation of the landslide.