Mössbauer Effect of Metastable bcc and fcc Fe–Cu Alloys Produced by Vapor Quenching

Abstract

Mössbauer spectra were obtained at 4.2 K and 290 K for the metastable bcc and fcc phases of sputtered Fe1−xCux alloys. For x=0–0.4 (the bcc phase region), a ferromagnetic sextet was observed at both 4.2 K and 290 K. The halfwidths of spectra are narrow and the average hyperfine field slightly decreases with increasing x. For x=0.6–1.0 (the fcc phase region), a sextet with very broad halfwidths was observed at 4.2 K. The average hyperfine field is smaller than that of the bcc alloys and gradually decreases with increasing x. At 290 K, where the fcc alloys are paramagnetic, a broad quadrupole splitting is detected, which can be decomposed into several contributions of Fe atoms with different numbers of nearest neighbor Fe atoms.