Low temperature properties of nanocrystalline Fe73.5Cu1Nb3Si13.5B9 ribbons

Abstract Many investigations on nanocrystalline samples were performed between room temperature and elevated temperatures but there is still a lack of low-temperature studies especially that of coercivity and magnetostriction. In this work we present measurements of the low-temperature behavior of magnetic properties like coercivity, magnetization and magnetostriction of Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 samples at different stages of crystallization and also in comparison to the amorphous state. The temperature dependence of the magnetostriction was measured by the small-angle magnetization rotation method which exhibits a high sensitivity. The magnetization data of the samples were used for analyzing the temperature dependence of magnetostriction in the low-temperature range in order to obtain information about the physical mechanism of the magnetostriction for such a kind of samples. From the temperature dependence of the magnetization, which follows the Bloch T 3/2 law, the spin wave stiffness constant can be estimated. The temperature dependence of coercivity H c below room temperature is also discussed.