Co-based magnetic microwire and field-tunable multifunctional macro-composites

Structural, magnetic and mechanical properties of Co-based magnetic microwires and their composites had been investigated. It was found that annealing amorphous microwires at 600 degrees C caused a drastic variation in the amorphous structure due to crystallization and consequently degraded the soft magnetic properties of the microwires. The tensile tests on the single microwires of different size with and without glass-coated layer revealed a coherent correlation between the mechanical properties and the wire geometry. When compared with single magnetic microwires, the magnetic and magneto-impedance properties of composites were much improved. The strong field dependence of the effective permittivity and transmission/reflection parameters in the Gigahertz range of the composites containing short wires or arrays of continuous wires indicated that these new composites are promising candidate materials for a variety of self-sensing applications. (C) 2009 Elsevier B.V. All rights reserved.