NUCLEAR ORIENTATION AS A TOOL FOR INVESTIGATION OF MAGNETIC MULTILAYERS WITH RARE-EARTHS

Low-temperature nuclear orientation (NO) is presented as a useful tool to study the behaviour of rare earth (RE) ionic magnetic moments in m agnetic multilayers. NO is shown to give rather direct information abo ut the direction of RE ionic moments in such low-dimensional systems. In particular, the perpendicular magnetic anisotropy (PMA) can be dire ctly monitored using RE atoms as probes. The potential of NO is demons trated by our recent results, which concern the Fe/Tb multilayers. We have studied NO of Tb-160 in Fe(40 Angstrom)/Tb(x Angstrom) (x = 5-30) and found that the Tb magnetic moments show PMA at low external magne tic fields (B-ext). PMA of the Tb spins is found to be more pronounced when the Tb layer is thinner. It was found that B-ext has a complicat ed influence on the Tb magnetic moment misalignment, which is connecte d with an interplay between PMA, the exchange interactions and the sha pe and magnetic crystalline anisotropy.