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

摘要

A magnetostrictive element for use in a magneto-mechanical marker has aresonant frequency characteristic that is at a minimum at abias field level corresponding to the operating point of the magnetomechanicalmarker. The magnetostrictive element has amagnetomechanical coupling factor k in the range 0.28 to 0.4 at the operatingpoint. The magnetostrictive element is formed by applyingcross-field annealing to an iron-rich (Fe) amorphous metal alloy (100) ribbon(45 to 82 percent iron) which includes a total of from 2 to 17percent of one or more of Mn, Mo, Nb, Cr, Hf, Zr, Ta, V. Cobalt (Co), nickel(Ni), boron, silicon and/or carbon may also be included. Themetal alloy (100) may include one early transition element selected from thegroup consisting of Zr, Hf and Ta, and also a second earlytransition element selected from the group consisting of Mn, Mo, Nb, Cr, andV.