Structure and growth of strained Cu films on Ru(0001)
Abstract We present X-ray scattering studies of the structure and growth of the heteroepitaxial interface Cu–Ru(0001) between 300 and 870 K. For Cu depositions of between one and two monolayers (ML), a bilayer stripe-phase coexists with domains pseudomorphic to the Ru substrate. At the completion of 2 ML, the stripe-phase wavevector abruptly locks to that of the substrate with a commensurability δ=1/16 or 1/18, depending on the temperature. Above 2 ML, a cooperative growth process leads to three-phase coexistence, including the bilayer stripe-phase and rotated and unrotated bulk-like Cu islands.