Epitaxy of ionic insulators on a vicinal metal substrate: KCl and RbI on Cu(211)

Ultrathin epitaxial films of the ionic insulators KCl and Rbl on Cu(211) we re investigated by high-resolution low-energy electron diffraction (SPALEED ). The Cu template employed is a vicinal surface which consists of (111)ter races separated by intrinsic monatomic (100) steps along the [011] directio n (step distance 6.25 Angstrom). The resulting uniaxial substrate corrugati on forces row matching between the intrinsic step separation and the charac teristic lattice parameters along low-indexed azimuthal directions of the a lkali halide layer. In this way, single-crystalline (100)-terminated films whose azimuthal orientations correspond to KCI[010] \\ Cu[011] and RbI[011] \\ Cu[011], respectively, are obtained. (C) 2000 Elsevier Science B.V. All rights reserved.