High-frequency phenomena in metallic bicrystals
Annotatsiya
The effect of two-dimensional defects (grain boundaries, twinning planes, and so on), parallel to the outer surface of the specimen, on the high frequency properties of metals in a strong magnetic field, when the characteristic radius of curvature of the trajectory of an electron r is much smaller than its effective mean free path l*, is investigated theoretically. It is shown that in the radio frequency range, where anomalous transparency of bicrystalline plates was observed,9 already for low probabilities for charge carriers to tunnel through an ideal intercrystallite boundary Q≫r/l*, the amplitude of electromagnetic field spikes does not depend on Q and coincides in order of magnitude with the spike intensity in a single crystal. The resonance dependence of the surface impedance on the magnetic field is investigated in the case when the frequency of the external wave is a multiple of the characteristic frequencies of the electrons, colliding with the boundary separating the crystallites. By studying the form of the resonance lines, it is possible to determine the probability Q and other characteristics that describe the interaction of electrons with two dimensional defects.