ENHANCED CURIE TEMPERATURES AND MAGNETOELASTIC DOMAINS IN DY LU SUPERLATTICES AND FILMS/

We have grown high quality superlattices of Dy with nonmagnetic Lu and find that the 2.4% epitaxial compression nearly doubles the ferromagn etic T(C) of Dy with little change in the Neel temperature. A helimagn etic phase exists over a narrow temperature range. Below T(C) in super lattices, 300 angstrom orthorhombic domains form despite epitaxial con straints, each with a magnetostrictive distortion comparable to that o f bulk Dy. For the thinnest intervening Lu layers, individual ferromag netic Dy blocks have parallel alignment; the remaining samples show an tiparallel alignment, coherent over many bilayer periods.