Observation of surface roughening on Ni(115)

Abstract

We present evidence that the equilibrium topography of the Ni(115) surface in the temperature range 100 K<T<1000 K is that expected above its roughening temperature. This conclusion is based on a detailed line shape analysis of the specular diffraction peak at anti-Bragg angles as a function of temperature. The experimental results are combined with a generic phase diagram for stepped (11m) surfaces of face centered cubic (fcc) metals and is estimated that the roughening temperature of Ni(115) is below 50 K, that of Ni(113) approximately 200±50 K, and that of Ni(001) well above 420 K.