$\mathrm{Mo}∕\mathrm{Co}\left(0001\right)∕\mathrm{Mo}\left(110\right)$ epitaxial films were grown by molecular beam epitaxy in ultrahigh vacuum on $\left(11\overline{2}0\right)$ oriented $\alpha \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3$ substrates. Co grows on Mo(110) in the Nishiyama-Wassermann orientation, i.e., $\left[1\overline{1}00\right]\mathrm{Co}\Vert \left[1\overline{1}0\right]\mathrm{Mo}$. Low energy electron diffraction reveals a lateral expansive strain of the Co film independent of the thickness. Magnetic anisotropies were obtained from hard-axis magnetization loops measured by Kerr magnetometry in longitudinal and polar geometry. Magnetic interface anisotropies are very small $(<0.04\mathrm{mJ}∕{\mathrm{m}}^2)$. Deviations of the volume-type in-plane $(K_{v,p}=0.79\mathrm{MJ}∕{\mathrm{m}}^3)$ and out-of-plane $(K_v=-9.5\mathrm{MJ}∕{\mathrm{m}}^3)$ anisotropies from bulk values for hexagonal-close-packed Co are attributed to magnetoelastic anisotropies.

• Received 28 November 2003

DOI:https://doi.org/10.1103/PhysRevB.70.184423