Abstract: | Polar profiles of directional elastic peak electron spectroscopy (DEPES) and directional Auger electron spectroscopy (DAES) were measured for the Cu(011) face in the vicinity of particular close-packed directions in the sample and for sample temperatures of 400<T<1200 K. For all directions investigated, the ln C versus T curve, where C is the contrast: C = 2(Imax?Imax)/(Imax + Imax) for a particular maximum in the polar profile, is composed of three linear parts. The slope of this particular part is different for the different maxima investigated but the breaks between the linear parts occur always at the temperatures T1 ≈ 700 K and T2 ≈ 1000 K. The former break is ascribed to the appearance of anharmonic thermal vibrations while the latter one indicates the surface roughening transition. DEPES was applied for the first time in the investigation of the surface roughening transition and it was found to be a very convenient and effective method. The surface roughening temperature TR ≈ 1000 K was found for the Cu(011) face, in an excellent agreement with theoretical predictions. |