Characteristic Electron Energy Loss Spectra of a Number of Solid Elements

The characteristic electron energy loss spectra of the elements gallium, indium, thallium, arsenic, selenium and tellurium have been obtained using the reflection technique and primary electron energies of 1500 and 800 eV. The results are discussed in conjunction with those for germanium, tin, lead, antimony and bismuth obtained by Powell in 1960. The spectra of all these elements comprise principally plasma and lowered plasma losses and combinations and multiples of these together with some losses associated with ionization and also, in Se and Te, a loss which is presumably due to an interband transition. The plasma loss peak is found to be narrower where there is agreement between the observed and theoretical plasma loss values and the relationship between these values is discussed. In conclusion, a résumé is given of the results which have been obtained for thirty-three elements using the same unit of equipment. In the elements other than the transition and noble metals, the excitation of plasma type oscillations is the dominant loss mechanism, almost to the exclusion of interband transitions, whilst the latter are of much greater importance in the complex spectra of the transition and noble metals. Ionization is observed in the majority of the elements studied.