Coinage-metal capping effects on the spin-reorientations of Co/Ru(0001)

Abstract

Thin films of Co/Ru(0001) are known to exhibit an unusual spin reorientation transition (SRT) coupled to the completion of Co atomic layers for Co thicknesses under 4 layers. By means of spin-polarized low-energy electron microscopy, we follow in real space the magnetization orientation during the growth of atomically thick capping layers on Co/Ru(0001). Capping with coinage-metal (Cu, Ag, Au) elements modifies the SRT depending on the Co and overlayer thickness and on the overlayer material, resulting in an expanded range of structures with high perpendicular magnetic anisotropy. The origin of the SRT can be explained in terms of ab-initio calculations of the layer-resolved contributions to the magnetic anisotropy energy. Besides the changes in the SRT introduced by the capping, a quantitative enhancement of the magnetic anisotropy is identified. A detailed analysis of the interplay between strain and purely electronic effects allows us to identify the conditions that lead to a high perpendicular magnetic anisotropy in thin hcp Co films.

25 pages, 10 figures. Corrected several typos, added a reference. The experimental and theory discussion has been rewritten in places for improved readability. The experimental observations are summarized in a table instead of a figure

References in corpus (1)

• Determining the structure of Ru(0001) from low-energy electron diffraction of a single terrace

Cited by in corpus (4)

• Perpendicular magnetic anisotropy of cobalt films intercalated under graphene
• Structure and magnetism in ultrathin iron oxides characterized by low energy electron microscopy
• Hydrogen-induced reversible spin-reorientation transition and magnetic stripe domain phase in bilayer Co on Ru(0001)
• Measuring the magnetization of three monolayer thick Co islands and films by X-ray dichroism