Electrons in rare-gas solids probed by EPR technique

With the use of an EPR device we have obtained spectra of unstable centers appearing as a solid gas layer was subjected to irradiation from an electrodeless discharge running in the gaseous Ne. The main feature of the spectrum is a singlet with g=2.000. Evidence is presented in favor of the spectrum being due to cyclotron resonance of free electrons emitted from the solid gas sample. An analysis of a linewidth and the spectrum structure allows a rough estimation of both the free electron density, ∼109 cm−3, and the lower limit of the electron kinetic energy, ∼200 K, to be made. Exceptionally strong signals have been obtained using rare-gas solids. A temperature dependence of the signal intensity above 4.2 K as well as processes leading to the electron emission are discussed. Another explanation of the signal origin as being due to electrons trapped in a matrix is also considered.