Magnetization behavior of thick epitaxial Gd(0001) films on W(110)

The temperature-dependent magnetic properties of thick Gd(0001)/W(110) films were investigated with respect to the annealing temperature as well as the film thickness (d=10–100 nm). After annealing to sufficiently high temperatures, thick films (d≥40 nm) show evidence for a canted magnetization, accompanied by a strong anomaly of the coercive field just below the Curie temperature ${\mathit{T}}_{\mathit{C}}$. These effects can be attributed to the temperature-dependent magnetic anisotropy of bulk Gd. For thinner films, the magnetization behavior implies the existence of residual strain, which cannot be fully annealed by thermal treatment. The implications of our experimental results for surface magnetic order are discussed.