Thermally stimulated desorption of ionized particles from the oxygen-activated Na/Au surface

Rapid Comm Mass Spectrometry

2021

Rationale The mass spectra of amine thermal ionization on intermetallic NaAux emitters differ significantly from those of the same compounds on the surfaces of transition metals and their oxides. The factors underlying these differences are determined through studying the processes taking place on intermetallic surfaces, which give rise to the corresponding mass spectra. Methods The dependence of mass spectral composition and individual line intensity of diethylamine thermal ionization on intermetallic NaAux surface on diethylamine pressure, oxygen, sodium atom current and emitter temperature was studied using a magnet sector mass spectrometer. Results Diethylamine mass spectral composition is determined by the reaction between the molecules adsorbed on the NaAux surface. Oxygen and sodium concentration on the surface does not affect the mass spectral composition. Mass line intensity depends on diethylamine pressure and emitter temperature affecting the reaction efficiency on the surface. Conclusions Intermetallic NaAux is an ionic semiconductor that can provide sufficient lifetime for adsorbed molecules to efficiently interact with each other and with their decomposition products. This creates unique conditions for the formation of various compounds on the surface with their mass exceeding by 2.5 times that of diethylamine.

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Section: Introductionmentioning

confidence: 99%

Formation of diethylamine thermal ionization mass spectrum on NaAu_x intermetallide

Rapid Comm Mass Spectrometry

2021

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“…The reaction results in the formation of amines and carbohydrates. The dehydrogenation reactions proceed independently on both sides of 19 This set of lines proves that n-azopropane adsorption involves redistribution of electron density, the b-bonds with N-atom group weakening either on one or on two sides. However, TI of n-azopropane is possible only for compounds formed during the first two stages of thermal decomposition of the adsorbed molecules.…”

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confidence: 75%

“…In order to obtain the NaAu y coating film on the emitter, the sodium was evaporated onto the gold ribbon by the method presented in literature. 19,20 The experiments were performed in the temperature interval of 700 K < T ribbon < 1200 K in a flux of sodium atoms with the intensity of I ¼ 10 12 -10 14 atom/(cm 2 Ás). Under these conditions, an ultrathin NaAu y film with the thickness of several atomic monolayers is formed on the gold ribbon surface.…”

Section: Fabrication Of Naau Y Filmmentioning

confidence: 99%

“…In literature 18 it was shown that when adsorbed at W x O y , TMT molecules achieve full thermal balance with the emitter, whereas ionization energy of TMT molecules V < 7.1 eV was estimated according to the temperature dependence of the ion current [M] þ from equation (1). During thermal ionization of diethylamide on NaAuy, ionization of compounds (-) and (M-R) is observed, 19,25 whose ionization energy is estimated at 7.2 eV b 7.8 eV, respectively, 1 suggests that when TMT molecules are desorbed from NaAu y surface, molecular ions should be registered.…”

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confidence: 99%

“…observed for amines on transition metal oxides. 1,11 Associated ions could also be formed by exchange reactions, as in 19,25,27…”

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confidence: 99%

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Thermal ionization of tetramethyltetrazene molecules on NaAu_y surface

Eur J Mass Spectrom (Chichester)

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2013

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