Epitaxial films of Sm1−xGdxAl2, a zero-moment ferromagnet

Bulk Sm 1-x Gd x Al 2 (0.003<x<0.02) compound exhibits an exciting magnetic property: its magnetic moment drops to zero at a compensation temperature T comp while it maintains a long-range ferromagnetic order. This compound is, therefore, an interesting candidate for electron spin analyzer or polarizer purposes. We achieved the epitaxial growth of (1 1 1) Sm 1-x Gd x Al 2 films by molecular beam epitaxy. Macroscopic magnetization measurements confirmed the existence of a magnetic compensated state occurring at a temperature that depends on the concentration of Gd. Specific features observed in the Sm 1-x Gd x Al 2 films are a strong [1 1 1] perpendicular magnetization direction and a very large coercivity.