A MOSSBAUER STUDY OF FE(5-ANGSTROM) PLUS CU(50-ANGSTROM) MULTILAYERS

Recent magnetic viscosity studies of Fe/Cu multilayer systems containi ng 5 angstrom layers of Fe sandwiched between 50 angstrom layers of Cu (111) have shown behaviour that is consistent with macroscopic quantum tunnelling of the magnetization. As part of a wider program of measur ements aimed at characterising this system, Fe-57 Mossbauer spectra of two samples grown in different laboratories were recorded at temperat ures ranging from room temperature to 4.2 K, and at 4.2 K in applied f ields of up to 5 T. The Mossbauer data show that one sample contains i ron oxide impurities, but that both samples contain roughly equal quan tities of ferromagnetic bcc Fe and antiferromagnetic fcc Fe. The Fe mo ments in both the bcc and fcc phases lie preferentially in the plane o f the multilayer film.