A polarized neutron reflectometry study of the spin glass freezing in a 29 nm thick AuFe film

Abstract

We performed polarized neutron reflectometry (PNR) experiments on a 29 nm thick Au 93Fe 7 film in a temperature range from 295 K down to 2 K in a vertical magnetic field up to 6 T. These high-field experiments were performed on the C5 spectrometer in Chalk River, Canada, using a split-pair cryomagnet. The magnetization as determined by PNR can be described with a Brillouin function from 295 K down to 50 K assuming the magnetic moment of isolated Fe atoms, i.e. 4 μ B per Fe atom. Below 50 K the onset of the spin-glass freezing is observed as a strong deviation from this Brillouin type behavior of isolated atoms.