LARMOR WAVES IN SINGLE-CRYSTAL COPPER AT 80 GHZ

Larmor waves have been studied using a transmission technique in thin plates of high-purity, single-crystal copper at a frequency of 80 GHz. Observations were made over the temperature range 425 K in magnetic fields 060 kG with the principal axes 100, 110, or 111 oriented perpendicular to the plane of the specimen. In contrast to earlier observations at 9 GHz, the present studies find a Larmor-wave period which is temperature dependent, and, at the lowest temperatures for certain orientations, an asymmetry in amplitude, with the Larmor-wave oscillations on the high-field side of the conduction-electron- spin resonance being considerably stronger than those on the low-field side. This behavior is not in complete agreement with present theory and may be due to a combination of many-body effects and the detailed geometry of the Fermi surface of copper. © 1990 The American Physical Society.