MAGNETOSTRICTIVE ELEMENT HAVING OPTIMIZED BIAS-FIELD-DEPENDENT RESONANT FREQUENCY CHARACTERISTIC

摘要

A magnetostrictive element for use in a magnetomechanical marker has a resonant frequency characteristic that is at a minimum at a bias field level corresponding to the operating point of the magnetomechanical marker. The magnetostrictive element has a magnetomechanical coupling factor k in the range 0.28 to 0.4 at the operating point. The magnetostrictive element is formed by applying current-annealing to an iron-nickel-cobalt based amorphous metal ribbon, or by cross-field annealing an iron-nickel-cobalt alloy that includes a few percent chromium and/or niobium.