The use of a linear resonator instead of a microwave resonant cavity increases the sensitivity of any resonance spectrometer when studying electron resonance in metals. This technique is used to study the temperature dependence of the line shape of the conduction-electron spin resonance in a lithium film for thicknesses ranging from 0.3 to 30 skin depths. Dyson's theory is found to apply at high temperatures. Deviations below 120 °K due to the anomalous skin effect provide a method of determining the microwave surface impedance in the alkali metals.

• Received 2 October 1969

DOI:https://doi.org/10.1103/PhysRevB.3.663