The studies of this series were extended to the negative ions of m⁄e 26 and 42 obtained from nitroalkanes; nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. For m⁄e 26 (probably, CN−) ions, the contribution of three or two processes in the range from zero to ∼20 eV of electron energy was observed for nitromethane or other samples. On the basis of ΔHf values of the reactants and products, and of the value of EA(CN), the plausible reactions to be assigned to each process were presented. For the first process, CH3NO2+e−→CN−+H2O+OH, RNO2+e−→CN−+R1OH+OH. For the second process, CH3NO2+e−→CN−+H2O+O+H, CH3NO2+e−→CN−+H2+O2+H, RNO2+e−→CN−+R1+HO2+H, and C3H7NO2+e→CN−+C2H4+H2+O+OH irrespective of kind of nitropropane. For the third process, CH3NO2+e−→CN−+3H+O2. For m⁄e 42 (probably, CNO−) ions, the contribution of two processes was observed. By taking ΔHf (CNO)=x (eV), EA(CNO)=y (eV), and also combining the observed onset values with the calculated values of appearance potential of reactions to be assigned for each process — for the first process, CH3NO2+e→CNO−+H2+OH, RNO2+e−→CNO−+R1OH+H; for the second process, CH3NO2+e−→CNO−+HO+2H, CH3NO2+e−→CNO−+H2+O+H, RNO2+e−→CNO−+R1O+2H– a relation of x−y\simeq2(eV) was derived.

Slightly Cu-rich CuGaSe 2 films were grown on ͓001͔ oriented GaAs substrates by molecular beam epitaxy. Photoluminescence of the films showed a remarkable emission peaked at 1.71 eV at low temperature, which is attributed to recombination of free excitons and bound excitons. The dissociation energy of free excitons and their localization energy to a center are found to be 16.2 and 3.3 meV, respectively. The band-gap energy E g is estimated to be 1.7310 eV at low temperature. It is suggested that the temperature variation of E g is dominated by interaction with phonons of 26 meV which corresponds to the mean energy of the optical phonons in CuGaSe 2 .

The ionization efficiency (IE) curves of NO2−, O− and CH2NO2− ions from nitroalkanes (nitro-methane, nitroethane, 1-nitropropane and 2-nitropropane) have been measured with a Hitachi RMU-6D mass spectrometer. Based on each authorized value of IP(CH3, C2H5, C3H7, O and H), D(C–NO2, C–H, C–C, NO–O and N–O), EA(NO2 and O) and the excitation energy of CH3, the respective onsets observed for the electron energies above ∼3 eV on the IE curves were suggested to be interpreted as appearance potentials of the following reactions. For NO2− ions, RNO2+e→R*+NO2−, RNO2+e→R+NO2−+e; for O− ions, RNO2+e→RNO+O−, RNO2+e→RN+O+O−, RNO2+e→RN++O+O−+e;for CH2NO2− ions, CH3NO2+e→H+ CH2NO2−+e, RNO2+e→H+R1+CH2NO2−. On the other hand, the strong peak of NO2− ions due to the dissociative electron capture process (RNO2+e→R+NO2−) was observed at the lower electoron energy. Furthermore, a value of EA(CH2NO2) was presented to be ∼0.5 eV.

The negative ion mass spectra of nitroalkanes (nitromethane, nitroethane, 1-nitropropane and 2-nitropropane) have been mesaured with a mass spectrometer under electron energies of 80 eV, 40 eV, 9.5 eV and 4.5 eV in the range of pressure used for usual analysis. The spectral intensities of negative ions were compared with those of positive ions. In 80 or 40 eV electron impact experiments, m/e 16 (O−), 46 (NO2−), 26 (probably, CN−) and 42 (probably, CNO− or C2H4N−) ions were commonly found. Their yields showed good linearity against pressure under the present experimental conditions. The peaks of m/e 61 (parent ion; CH3NO2−) in nitromethane, of m/e 25 (C2H−) in nitroethane, 1-nitropropane and 2-nitropropane, and a relatively strong peak of m/e 60 (CH2NO2−) in 1-nitropropane were characteristic. For lower electron energies, the strong dependency of the yield of negative ions on the electron energy was confirmed. The yield of negative ions as compared with positive ions for 80 eV and 40 eV of electron energy was lower by a factor of ∼104. On the other hand, the comparison of the yield of positive ions for 15 eV electrons with that of negative ions for 9.5 eV electrons gave the value of ∼0.2. In addition, of the role these negative ions in radiolysis has been briefly discussed.

The negative ion mass spectra of alkyl (methyl, ethyl, n- and iso-propyl) chlorides, with emphasis on their relative abundance to the positive ions under 80, 40, 20 and 15 eV electron energies, and the ionization efficiency (IE) curves of Cl− ions to the extent of 30 eV electron energies were measured. In every sample, the electron impacts of 80 eV and 40 eV gave almost the same distribution of m/e for negative ion mass spectra, in which, besides the intense peaks of m/e 35 and 37 (Cl−), a relatively strong peak of m/e 25 (C2H−) in ethyl chloride and n- and iso-propyl chlorides was characteristic. For 20 eV and 15 eV, Cl− ions predominated other negative ions. The ratio of the abundance of negative ions to positive ions was the order 102–103 for CH3Cl+/Cl−, C2H5Cl+/Cl−, C3H6+/Cl− and C3H7+/Cl− throughout the range of electron energies. Each onset value observed in IE curves was interpreted to correspond to the appearance of the following reactions, the reaction scheme for second process being tentative. For the first process RCl+e−→R+Cl−, for the second process CH3Cl+e−→H+CH2+Cl−, C2H5Cl+e−→H2+H+C2H2+ Cl−, C3H7Cl(n- or iso-)+e−→H+C2H4+CH2+Cl−. For the third process the possibility of ion pair formation was pointed out. For the fourth process in ethyl chloride a brief discussion was made in view of the overlapping phenomena of a complicated dissociative electron capture process with an ion pair formation.