Low damping magnetic properties and perpendicular magnetic anisotropy with strong volume contribution in the Heusler alloy Fe1.5CoGe

Abstract

We present a study of the dynamic magnetic properties of TiN-buffered epitaxial thin films of the Heusler alloy Fe${}_{1.5}$CoGe. Thickness series annealed at different temperatures are prepared and the magnetic damping is measured, a lowest value of $\alpha =2.18\times 10^{-3}$ is obtained. The perpendicular magnetic anisotropy properties in Fe${}_{1.5}$CoGe/MgO are also characterized. The evolution of the interfacial perpendicular anisotropy constant $K_{\mathrm{S}}^{\perp }$ with the annealing temperature is shown and compared with the widely used CoFeB/MgO interface. A large volume contribution to the perpendicular anisotropy of $(4.3\pm 0.5)\times 10^5$ $J/{\mathrm{m}}^3$ is also found, in contrast with vanishing bulk contribution in common Co- and Fe-based Heusler alloys.

5 pages, 5 figures