Resumo

LONDONO, Yeimy; PENA-LARA, Diego  e  DIOSA, Jesús E. PHASE BEHAVIOR OF NaH₂PO₄.H₂O AT HIGH TEMPERATURES. Momento [online]. 2016, n.52, pp.1-8. ISSN 0121-4470.

Abstract Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Impedance Spectroscopy (IS) were used to study the phase behavior of the system, NaH₂PO₄H₂O above room temperature. The DSC results show five endothermic anomalies with picks around 70°C, 120°C, 210°C, 325°C, and 350°C, during the first heating run, but any anomaly is show on the subsequent cooling run. The TGA results show that fresh powder of NaH₂PO₄H₂O loss weight when the sample is first heated across the different temperatures. The electrical resistance of fresh sample NaH₂PO₄H₂O also shows strong variation at 70^°C and 120^°C anomalies, indicating that the ionic transport is enhanced between 55°C and 108°C, and between 120°C and 150°C. We discuss and attributed the observed behavior in NaH₂PO₄H₂O throw the different temperatures, where observed the anomalies, as a consequence of a dehydration process of the sample.

Palavras-chave : NaH₂PO₄; Electrical Resistance; DSC; TGA.

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