Low-temperature magnetization and magnetic exchange interactions in Fe40Ni40P14B6 bulk metallic glasses

Abstract

One of the fundamental magnetic properties – the low-temperature magnetization as well as the exchange interactions derived by using a spin-wave excitation theory – has been well studied in glassy ribbons rather than bulk metallic glasses. The paper studies the temperature-dependent magnetization of a bulk Fe40Ni40P14B6 alloy, derives the range and fluctuation of exchange interactions, and compares these magnetic behaviors with those of well-studied glassy ribbons. The low-temperature magnetization of our bulk glass can be well expressed by a spin-wave excitation theory, which has been widely utilized to study the temperature-dependent magnetization of ferromagnetic glassy ribbons. Moreover, both the derived spin-wave stiffness coefficient and the derived range and fluctuation of exchange interactions in our bulk metallic glass are very similar to those in glassy ribbons, indicative of the similarity in magnetic exchange interaction between bulk metallic glasses and glassy ribbons.