Design of magnetic properties of arrays of magnetostatically coupled glass-covered magnetic microwires

We have studied magnetization reversal in arrays consisting of different numbers of Co67Fe3.9Ni1.5B11.5Si14.5M1.6 and Fe74B13Si11C2 amorphous microwires with different shape of the hysteresis loops. Fe74B13Si11C2 microwires have rectangular hysteresis loops, while Co(67)Fe(3.9)Ni(1.5)Bl(1.5)Si(14.5)M(1.6) with vanishing magnetostriction constant possess inclined hysteresis loops with low coercivity. The presence of a neighboring microwire (Fe- or Co-based) significantly modifies the hysteresis loop of the whole microwire array. In microwire arrays containing Fe-based microwires we observed splitting of the initially rectangular hysteresis loop with a number of Barkhausen jumps correlated with the number of Fe-rich microwires. In arrays consisting of Co-based microwires we observed a change of inclination of the overall hysteresis loop and consequently the magnetic anisotropy field. In the case of mixed arrays containing Fe- and Co-rich microwires we were able to obtain irregular hysteresis loops with unusual shape. In this case, a considerable increase of harmonics has been observed. The observed dependences have been interpreted through magnetostatic interaction between the microwires with different magnetic domain structures. Besides the conventional methods, such as thermal treatment, designing arrays containing different types of microwires can serve to tailor their magnetic properties.(c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim