title: Raman spectroscopic investigation on Jarosite-Yavapaiite stability.
abstract: The stability of synthetic Jarosite (KFe(3)(SO(4))(2)(OH)(6)) at low temperature and reduced atmospheric pressure has been studied by Raman spectroscopy. Jarosite remains stable between 8 and 295 K, provided that the sample is not exposed to reduced atmospheric pressure. When exposed to reduced atmospheric pressure (2.0x10(-2) Torr), however, the conversion of Jarosite into a different mineral is readily detected at room temperature by the appearance of a new Raman peak. The Raman shift of this peak (1032 cm(-1)) matches with that of Yavapaiite (KFe(SO(4))(2)), which can be obtained by thermal decomposition of Jarosite above 473 K. These studies provide a better understanding of the stability of Jarosite subjected to conditions similar to that on the surface of Mars.
authors.affiliation: Department of Chemistry, University of Hawaii, Honolulu, HI 96822, USA.
authors.forename: Chi Hong
authors.initials: CH
authors.lastname: Chio
authors.forename: Shiv K
authors.initials: SK
authors.lastname: Sharma
authors.forename: Li-Chung
authors.initials: LC
authors.lastname: Ming
authors.forename: David W
authors.initials: DW
authors.lastname: Muenow
mesh_terms: D001274:Atmospheric Pressure; D018559:Exobiology; D005118:Extraterrestrial Environment / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry; D011188:Potassium / Q000737:chemistry*; D018561:Space Simulation; D013059:Spectrum Analysis, Raman; D013431:Sulfates / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D013431:Sulfates; C492331:jarosite; D014867:Water; D011188:Potassium