Crystallographic anisotropy of the reflection of conduction electrons from a sample surface in bismuth

The crystallographic anisotropy of the probability of specular reflection q of conduction electrons from a sample surface in Bi and the effect of chemical and ion etching of the trigonal plane on the character of the electron reflection were studied experimentally with the help of electron focusing with a transverse magnetic field. It was found that q is large (≈ 0.8) for surfaces close to the trigonal plane. Inclination of the sample surface from the trigonal plane by an angle greater than 20° and etching of the surface of the samples suppressed the specularity (q ≈ 0. 1 − 0.2). The results are discussed from the viewpoint of electron scattering by a rough surface and by adsorbed, randomly distributed, charged impurities.