Transverse conduction electron focusing and specular reflection in aluminium single crystals

Transverse electron focusing (TEF) of the second-zone hole surface orbits in aluminium single crystals has been observed and used to investigate the probability (p) of specular reflection of conduction electrons at sample surfaces for the three principal crystallographic planes-(100), (110) and (111). The p-values obtained range from 0 to 0.61+or-0.05 depending on both the crystallographic plane and the geometry of the orbit when the surfaces are electrochemically polished like a mirror. Even on the chemically etched dull surface, up to a quarter of conduction electrons are specularly reflected. For specific orbits, the signal shapes are compared with those computed from the four-OPW Fermi surface model.