Hydrated Magnesium Sulfates below 0 °c -- Stable Phases and Polymorphs
نویسندگان
چکیده
Introduction: The identification of hydrated MgSO4 on Mars [1,2,3,4,5,6,7] provides a potential reservoir for retaining martian water in the solid phase [8]. A clarification of the stability fields and phase transition pathways of the MgSO4·nH2O salts above 0 oC (Fig. 1) helped in determining the potential candidates that might exist in the martian environment [9, 10,11,12,13]. The recent report on the discovery of a low temperature hydrated sulfate meridianiite MgSO4·11H2O [14] makes it even more imperative that the studies on the stability field and phase transition pathways of the hydrated Mg-sulfates be extended below 0 °C. This is especially important in light of the Phoenix mission for verifying the existence of meridianiite at the Mars polar region. The study we report here was undertaken to extend our study on Mgsulfates to -10 oC over a wide range of relative humidities (RH) in order to: (a) establish the stability field of meridianiite; and (b) determine what other stable hydrated Mg-sulfates exist at -10 oC.
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