Lattice-stiffening transition in gadolinium chains on furrowed (112) surfaces

Abstract

A lattice-stiffening transition is observed near 230 K in corrugated 'chain like' gadolinium structures formed on Mo(112) and W(112). This transition is evident from the change in the effective Debye temperature. Below the transition temperature of 230 K the gadolinium overlayer lattice has much higher effective Debye temperature than that observed for higher temperatures (for the quasi-one-dimensional Gd sub-monolayer structures or for the higher coverage overlayers). From model studies, lateral dipole–dipole and indirect interactions as well as the interaction between the adatoms and the substrate play an important role in this transition.