The influence of long-range dipole-dipole interaction on the coercivity of
an array of glass-coated CuNiCo microwires is investigated by means of magn
etic hysteresis measurements and Monte Carlo simulations. The microwires ex
hibit a granular structure consisting of Co grains in a Cu-rich matrix. Hys
teresis loops for an array of N microwires (1 < N < 100), performed at room
temperature, show that Hc changes abruptly from 20 to 700 Oe for N around
10. This property allows us to tune H-C choosing N, and promises to be usef
ul for practical applications. (C) 2001 Elsevier Science B.V. All rights re
served.