Evaluation of use of magnetically bistable microwires for magnetic labels

The dynamics of the magnetization reversal by means of head-to-head domain-wall propagation is investigated both experimentally and theoretically for magnetic labels made from Ferich bistable glass-coated microwires. It is shown that the amplitudes of the electromagnetic harmonics generated by bistable Fe-rich magnetic labels of the length 1-4 cm with metallic nuclear diameter of 10-20 mu m are more than 5 times larger than that of similar labels made of Co-rich microwires having high permeability and low coercive force. The electromagnetic harmonics can be detected at the distances up to 1520 cm from the magnetic label at the signal-to-noise ratio not lower than 2.0. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim