The magnetostriction of CoFeNiMo metallic glasses measured with a tunneling transducer

Abstract

The longitudinal magnetostriction as a function of the Co/Fe content of the metallic glass series Co 72− x Fe x Ni 3 Mo 1Si 12B 12, for 0 ≤ x ≤ 10, is reported. The measurement is performed using a novel technique, based on electron tunneling, which provides a highly sensitive, noncontact, quasi-dc and direct measurement of magnetostrictive strains. The minimum value of the longitudinal magnetostriction measured is (−1.65±0.24) ppm for 0% Fe, and the maximum (in this composition range) is (2.51±0.15) ppm for 10% Fe, with a zero-magnetostriction composition of 5.25% Fe. These data are compared to those previously reported for a similar metallic glass series, but with higher Mo content. Increasing the Mo content in these glasses is shown to decrease the Fe content at the zero-magnetostriction composition point.