Thermal properties of indium tris-dipivaloylmethanate as a volatile precursor for indium oxide materials

Abstract

Thermophysical and thermochemical data including condensed and vapor phase transformations and temperature stability ranges, melting, sublimation and vaporization processes for a volatile metal-organic precursor are of current importance to optimize the preparation of functional nano-materials through chemical vapor deposition, atomic layer deposition and their modifications. Here, we present the results of a comprehensive thermal characterization of indium tris-dipivaloylmethanate, In(thd)3 or In(dpm)3, which is a convenient air-stable precursor for widely demanded indium oxide ceramics. Thermogravimetry was applied to evaluate the condensed phase stability both in inert and oxidizing atmosphere. The melting temperature and enthalpy were measured by differential scanning calorimetry. The pressure of saturated and unsaturated In(thd)3 vapors was measured using a static method with glass membrane-gauge manometer. The p(T) equations of saturated vapors over the solid and liquid complex were obtained and the thermodynamic characteristics of the processes under study were calculated. The thermal decomposition of In(thd)3 vapors on a heated surface in vacuum and in oxygen presence was investigated by in situ mass spectrometry. The temperature range of this process and its intramolecular character were revealed. A critical review of the literature data on the thermal properties of In(thd)3 was also performed.