Asymmetrical magnetoimpedance in as-cast CoFeSiB amorphous wires due to acbias

Asymmetrical giant magnetoimpedance (AGMI), which utilizes a high frequency bias field h(b), is realized in a Co-based amorphous wire having a circumf erential anisotropy in the outer region. No asymmetry in the dc magnetic co nfiguration is needed in this case. AGMI is discussed in terms of the surfa ce impedance tensor, demonstrating that the effect of h(b) is related to th e role of the off-diagonal component of the impedance in the voltage respon se measured across the wire. This effect is important for developing autobi ased linear magnetic sensors. Using two oppositely biased wires, a near-lin ear voltage output (+/- 4 mV) is obtained in the range of +/- 5 Oe for the sensed dc field at a frequency of 8 MHz. (C) 2000 American Institute of Phy sics. [S0003-6951(00)03927-9].