Transmission of Low-energy Electrons (0–15 eV) through Thin Films of Ethers, Ketones, Alcohols, and Ice. Determination of the Quasifree Electron State Energy

Abstract

Abstract The transmission of low-energy electrons (0–15 eV) through 10–100 Å films of ethers, ketones, alcohols, and ice has been studied. Structures are indicated by electron current It transmitted through a thin film as a function of the incident electron energy Vi, displayed as dIt⁄dVi vs. Vi. With increasing the film thickness, a decrease of the height of the first peak (due to injection of electrons in the film) and an appearance of a second peak are observed for ethers and alcohols. The energies of quasifree electron state V0 are determined by measuring the energy of the second peak from the first peak for solid diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-nonanol. For acetone, diethyl ketone, dimethyl sulfoxide, and ice, neither a decrease of the first peak nor an appearance of a second peak is observed, indicating that these compounds have negative V0 values. From the energy of the onsets of broad negative peaks appeared at ≈14 eV for ethers and alcohols, the solid phase ionization energies IS and the polarization energies of cations P+ by the solid media are determined.