2008 年 29 巻 11 号 p. 659-664
Energy spectra of field emission electrons from some materials at different temperatures are reviewed in the practical points of views; they are conventional refractory metals, multi-walled carbon nano-tubes, Nb superconductors and single-atom electron sources. While the spectra of conventional refractory metals are explained well on the basis of Folwer-Nordheim theory, those of the other systems are not; the main peak with a different shape appears in the spectra of CNT, the extra peaks overlap in addition to the main peak of CNT and the single-atom electron sources. An extra sharp peak appears at the Fermi level of the spectra of a Nb superconductor.