Magnetic properties and hyperfine interactions of amorphous Fe‐Hf alloys Available to Purchase

Alloys of Fe_xHf_100−x (20≤x≤100) were fabricated by a vapor‐quench method. The amorphous state, as verified by x‐ray diffraction, is realized over a wide composition range of 20≤x≤94. The magnetic phase diagram was determined. The variation with Fe content of the magnetic ordering temperature (T_c) in Fe‐Hf amorphous alloys shows a maximum at x_p≂87. In contrast, the effective magnetic hyperfine field and therefore the Fe moment increases monotonically with x. Amorphous pure Fe is likely to be magnetic (T_c ∼200 K) with a large magnetic moment. At higher Fe concentrations (x>95), the samples are crystalline alloys and strongly ferromagnetic. These sharp changes of the magnetic properties are consequences of structural differences, a fact which has been observed in every Fe‐early transition metal alloy system reported thus far. In general, the magnetic properties and hyperfine interactions of amorphous Fe‐Hf alloys are very similar to those of amorphous Fe‐Zr alloys.