title: Observation of impurities in ice.
abstract: This paper presents a new method for determining the microstructural location of impurities in polycrystalline ice, which involves allowing the ice to sublimate under vacuum and then identifying the concentrated impurities using energy dispersive X-ray microanalysis in a low-vacuum scanning electron microscope. The method allows the presence of impurities in both the grain boundaries and the lattice of natural polycrystalline ice to be observed. Using this technique on natural ice, filaments consisting chiefly of NaCl were observed in some grain boundaries, small amounts of sulfur and chlorine were found in the grain interiors of the ice, and large concentrations of sulfur were observed in inclusions.
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755-8000, USA.
authors.forename: D
authors.initials: D
authors.lastname: Cullen
authors.forename: I
authors.initials: I
authors.lastname: Baker
mesh_terms: D004577:Electron Probe Microanalysis; D007053:Ice / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D012965:Sodium Chloride / Q000032:analysis; D013464:Sulfuric Acids / Q000032:analysis
chemical_list: D007053:Ice; D013464:Sulfuric Acids; D012965:Sodium Chloride; C033158:sulfuric acid