Vaporization thermodynamics of In2 O3 by Knudsen effusion mass spectrometry. The standard enthalpy of formation of In2 O(g).

In2 O3 is one of the most important semiconductor oxides in modern electronics. Vacuum deposition methods are often used for the preparation of In2 O3 -based nanomaterials. Thus, vaporization thermodynamics is of key importance for process control and optimization. Since the literature data on the vapor composition and partial pressure values for In2 O3 are contradictory, vaporization thermodynamics of In2 O3 needs to be clarified. Vaporization behavior of In2 O3 was studied using the Knudsen effusion technique in the temperature range 1400-1610 K. Quartz effusion cells were employed. A magnet mass spectrometer with an ordinary focus and a sector-type analyzer was used. Heating of samples and molecular beam ionization were performed by electron impact. The operating ionizing electron energy was 75 eV. A specially designed experiment allowed us to determine the individual mass spectrum of the In2 O molecule and, thus, to interpret the mass spectrum of the vapor registered during In2 O3 vaporization. The composition of the equilibrium vapor was quantified and the partial pressures of the vapor species were determined. On the basis of the experimental data, the standard enthalpies of some gaseous and heterogeneous reactions taking place during In2 O3 vaporization and the standard enthalpy of formation of In2 O(g) were calculated. The presence of In species in the vapor over In2 O3 was confirmed and the vapor composition was quantified. Thermodynamic characteristics of In2 O3 vaporization were obtained and a value of the standard enthalpy of formation of In2 O(g) was recommended. These data can be used for further thermodynamic calculations and for evaluating parameters for the synthesis and exploitation of In2 O3 -containing materials. © 2021 John Wiley & Sons Ltd.

Citation

Andrey S Smirnov, Nadezhda A Gribchenkova, Andrey S Alikhanyan. Vaporization thermodynamics of In2 O3 by Knudsen effusion mass spectrometry. The standard enthalpy of formation of In2 O(g). Rapid communications in mass spectrometry : RCM. 2021 Aug 15;35(15):e9127

PMID: 34014580

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