  Thin films of the proposed topological insulator PdLuBi - a Heusler compound
with the C1b structure - were prepared on Ta-Mo-buffered MgO(100) substrates by
co-sputtering from PdBi2 and Lu targets. Epitaxial growth of high-quality
PdLuBi films was confirmed by X-ray spectrometry and reflection high-energy
electron diffraction. The root-mean-square roughness of the films was as low as
1.45 nm, although the films were deposited at high temperature. The film
composition is close to the ideal stoichiometric ratio. The valence band
spectra of the PdLuBi films, observed by hard X-ray photoelectron spectroscopy,
correspond perfectly to the ab-initio-calculated density of states.
