Collective processes in thermal ionization on the surface of NaAu-=SUB=-x-=/SUB=- intermetallic compound

Abstract

A mechanism is proposed for the decomposition of molecular clusters of diethylamine (C2H5)2NH on the surface of the NaAux intermetallic compound with the formation of decomposition products desorbed from the surface, including in the form of ions with m/z from 58 to 197, during heating of the intermetallic compound at a rate of 20 K/s. Exposure of the NaAux surface at a temperature of 320 K in diethylamine vapor leads to the formation of molecular clusters on it. Rapid heating of NaAux at a rate of 20 K/s leads to the decay of clusters, desorption, and ionization of the decay products due to the redistribution of internal energy over the degrees of freedom of the cluster. The study of thermal ionization processes during heating of NaAux at a rate of 20 K/s in the temperature range from 600 to 1000 K made it possible to establish that the surface stoichiometry during heating is quasi-stationary, dehydrogenation and ionization of individual diethylamine molecules occur under equilibrium conditions, while for compounds formed in the process of cluster decay, the conditions are not equilibrium. Keywords: thermal ionization, diethylamine, intermetallics, sodium, gold.