Laser annealing effect on giant magnetoimpedance in amorphous Co-based microwire

Summary form only given. Many works on the giant magnetoimpedance (GMI) have been studied in amorphous microwires with diameters of few ten /spl mu/m due to large GMI effect. In this work, Co-based microwire is annealed by pulsed Nd:YAG laser at various annealing energy between 122/spl sim/142 mJ/pulse in air. The Nd:YAG laser was Kr-lamp pumped and consisted of a Nd:YAG rod of /spl phi/5 mm/spl times/70 mm(plane/plane), a full mirror and output coupler (30% transmission). The lasing wavelength is 1.064 /spl mu/m and the pulse width is 220 /spl mu/s. The authors present the GMI ratio profile measured at 10 MHz for the laser-annealed samples at 122 mJ. This shows asymmetric and hysteric profiles for cyclic field H. They also show the variation of maximum GMI ratio(/spl Delta/Z/sub max//Z) and ratio difference between two asymmetric peaks (/spl Delta/Z/sub p//Z) with annealing energy. Both of /spl Delta/Z/sub max//Z and /spl Delta/Z/sub p//Z show largest value at 127 ml/pulse (peak power is /spl sim/620 W). The effect of laser annealing on GMI profile are associated with microstructural change.