The use of a new inelastic electron tunnelling spectrometer in the study of isomers of benzenedicarboxylic acid

Abstract

A spectrometer is described with particular reference to its resolution and to a novel quick change specimen holder. For the benefit of new workers in the field, the need for four-point probe measurements is reiterated, together with the importance of suitable cleaning procedures during sample preparation and rigorous electrical screening of the spectrometer. A high resolution spectrum of benzoic acid is presented together with spectra of 1,2-, 1,3-and 1,4-benzenedicarboxylic acids. Brief mention is made of the use of a computer data acquisition system with the latter, full details being described elsewhere.

Characterization of Metal Oxide Surfaces and Thin Semiconductor Films by Inelastic Electron Tunneling Spectroscopy

“…5,17,[25][26][27] The peak positions of the spectrum were corrected by -1 meV (-8 cm -1 ) owing to the energy gap of the superconducting Pb electrode. 7 The x axis of the x-y recorder was calibrated with a standard voltage generator.…”

“…In this section, studies on organic acids and related compounds, 1,2,6,12,[16][17][18][19][25][26][27]30,36, esters, 12,19,[95][96][97][98][99] amides, [100][101][102] and nitryls 102 are introduced and reviewed.…”

“…They concluded that although these aliphatic dicarboxylic acids are adsorbed as monocarboxylate anions on the surfaces, the νC=O peak of the COOH group in the tunneling spectra is attenuated by the presence of the Pb top electrode from a comparison of the MRAIR spectra. 63,64 The tunneling spectra of benzoic acid 5,17,18,[25][26][27][66][67][68][69][70]83 and various related compounds [16][17][18]26,41,51,56,65,[69][70][71][72][73][74][75][76][77][78]80,81,83 were measured and reported. Benzoic acid is adsorbed as benzoate anion on alumina and magnesia, giving a good tunneling spectrum with strong and well-resolved peaks.…”

“…16,17,26,56,[69][70][71][72][73][75][76][77][78]80,81 Monjushiro et al 76 measured the tunneling spectra of various o-substituted benzoic acids on alumina and studied the interaction of the substituted groups with the surface. They reported that the -COOH, -OH, and -SH groups interact strongly in this order, but the -NH2, -F,…”

“…Information on their structures and orientations on the oxide surfaces can be obtained by examining the characteristic C=O group. 16,17,26,78,81 The tunneling spectra of phthalic, isophthalic, and terephthalic acid on alumina and magnesia doped from the gas phase are shown in Figs. 12 and 13, respectively.…”