Development of a combined dilatometer and mass spectrometer system for studying gas phase chemistry and kinetics during sintering

An in-depth analysis of the components and materials comprising the combined dilatometry mass spectrometry (CDMS) apparatus is provided. This includes recent modifications, operating procedures and information on how and why major system failures have occurred. The CDMS system is then used to study the gas phase reactions that occur during the sintering of strontium titanate. Two families of peaks, mass to charge (m/z) ratios 44 and 64 being the primary peaks, are consistently observed prior to the onset of sintering. Based on isotope ratios, cracking patterns, and comparisons to the decomposition of model compounds, these gases have been identified as carbon dioxide and sulfur dioxide respectively. Quantitative analysis was performed by comparing the primary peak size from the strontium titanate sample to the decomposition of the model compounds, showing that these two gases can account for between 60 to 200% of the observed weight loss. This range is because it is unclear whether the carbon and sulfur reacted with oxygen occurring in the crystal matrix, or with trace oxygen in the atmosphere.