Study of Helimagnetism in Dy/Ho Superlattice by Neutron Reflectometry

The results of studying a superlattice of alternating layers of rare-earth helimagnets [Dy(6 nm)/Ho (6 nm)] × 34 by neutron reflectometry and X-ray diffraction are presented. It is shown that during the growth of helimagnetic structures on sapphire substrates with a Nb buffer layer by magnetron sputtering, the orientational relations ( 11̅02) Al 2 O 3 ||(110)Nb|| ( 0001) (Dy/Ho) and the crystal lattices of Nb and the structure of rare-earth helimagnets are completely relaxed. It is also found that two different magnetic helicoids are formed in the sample, propagating coherently in Dy and Ho layers, respectively, with periods and Néel and Curie temperatures that differ from the characteristic temperatures of single crystals and thin one-component Dy and Ho films.