17787-49-4Relevant academic research and scientific papers
Preparation and characterization of coprecipitates and mechanical mixtures of calcium-strontium oxalates using XRD, SEM-EDX and TG
Knaepen,Van Bael,Schildermans,Nouwen,D'Haen,D'Olieslaeger,Quaeyhaegens,Franco,Yperman,Mullens,Van Poucke
, p. 143 - 153 (2008/10/09)
In view of the study of the chemistry of the oxalate coprecipitation process for preparing BiSrCaCuO superconductors, the characteristics of oxalates of calcium and strontium in the Ca(NO3)2-Sr(NO3)2-HNO 3-H2O-(NH4)2C2O 4 system are investigated. Based on XRD, SEM and TG a comparison between the crystal structure, morphology and thermal decomposition behavior of coprecipitated and physically mixed calcium and strontium oxalates with the same Ca/Sr stoichiometry is made. It is shown that the coprecipitated powders form homogeneous solid solutions of which the crystal structure, morphology and thermal behaviour depend on the Ca/Sr stoichiometry.
Preparation and thermal decomposition of various forms of strontium oxalate
Knaepen,Mullens,Yperman,Van Poucke
, p. 213 - 227 (2008/10/09)
Strontium oxalate exists in two different forms: the neutral strontium oxalate hydrate, SrC2O4·xH2O, and the acid salt of strontium oxalate, SrC2O4·yH2C2O 4·xH2O. Depending on the concentration of oxalic acid and ammonium oxalate as precipitating agents, both forms can be obtained. At a sufficiently low pH, the stoichiometric compound SrC2O4·1/2H2C2O 4·H2O is formed. The thermal decomposition of the different strontium oxalates is studied in different atmospheres using DSC, and TGA coupled with FTIR and MS. The TGA-EGA spectra indicate that the anhydrous acid oxalate decomposes with the release of H2O, CO, CO2 and formic acid.
