Electron Spin Resonance in Fine Particles of Metallic Lithium

Abstract

Fine particles of metallic lithium of diameters from about 3000 to 100Å were prepared by the evaporation method in an inert gas atmosphere. The relaxation of conduction electron spins in those particles was measured by an X-band spectrometer at room temperature. The line of the electron spin resonance broadened from 2.7 to 8.2 Oe as the particle size was reduced from about 3000 to 1000Å. This effect is explained by the spin reverse scattering at the surface of the particles. As the particle size was further reduced, the line narrowed remarkably. The width for 100Å particles was 1.9 Oe. This effect is discussed in connection with the quantization of electronic energy levels in fine particles. The measurement was also carried out at liquid helium temperature. However, on remarkable change was observed.