Magnetic domain structure of ferromagnetic Tb(0001) films

Raw data used for the manuscript: "Magnetic domain structure of ferromagnetic Tb(0001) films" published in Physical Review B. In this study we present the results of a spin-polarized scanning tunneling microscopy study performed on epitaxial Tb(0001) films grown on W(110). The magnetic contrast was obtained by dipping the tip directly into the Tb film, thereby creating magnetic in-plane sensitive tips. Our differential conductance dI/dU data reveal contrast levels which are in agreement with the tunneling magnetoresistance effect between an in-plane sensitive scanning tunneling microscopy tip and surface domains magnetized along basal <10-10> directions. Film-thickness-dependent studies reveal a close correlation between the structural and magnetic properties of the film. Four types of crystal defects are identified which contribute to the pinning of magnetic domains: (i) surface step edges, (ii) step dislocations, (iii) structural boundaries between differently stacked terbium (Tb) patches, and (iv) screw dislocations resulting from glide processes. As the thickness of the Tb film increases, the defect density diminishes, leading to the formation of larger domains. A detailed analysis of the domain walls leads to the conclusion that they are of Néel type and exhibit a width of w60 ≈ 1.4 nm, w120 ≈ 2.5 nm, and w180 ≈ 3 nm for 60°, 120°, and 180° domain walls, respectively.