Leed and Rheed Studies of COPPER(110) from 153 TO 983 K

Low-Energy Electron Diffraction (LEED) and Reflection High-Energy Electron Diffraction (RHEED) were applied for studying the surface structure and surface thermal phenomena of clean Cu(110) over a wide range of temperatures from 153 K to 983 K. A full LEED dynamical analysis was performed using Layer-Doubling method. The LEED analysis shows the presence of multilayer relaxations with a damped oscillatory. This is expressed as a contraction of the first interlayer spacing, followed by an expansion of the second interlayer spacing. The surface and bulk Debye temperatures were determined. Both the interlayer spacings and Debye temperatures were found to be anomalously changed for the temperatures above 570 K. The LEED results indicate the presence of anharmonicities on the clean Cu(110) surface at high temperatures. RHEED specular beam spot profile measurements as a function of temperature show a dramatic decrease in the scattering intensity around 550 K. The RHEED patterns show the disappearance of the Kikuchi lines at temperatures above 800 K. The results of this work suggest that anharmonic effects precede the onset of a rough surface at about 800 K.