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SEM/EDS comparison of polar and seasonal temperate ice
Author(s) -
Obbard Rachel,
Iliescu Daniel,
Cullen Daniel,
Chang Janelle,
Baker Ian
Publication year - 2003
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.10381
Subject(s) - impurity , scanning electron microscope , microstructure , grain boundary , energy dispersive x ray spectroscopy , materials science , analytical chemistry (journal) , chemistry , mineralogy , composite material , chromatography , organic chemistry
We have developed a method employing a scanning electron microscope (SEM) and energy dispersive X‐ray spectroscopy for examining uncoated ice specimens. By permitting the ice to sublimate in the SEM at temperatures between −115° and −60°C, enough ions are produced to prevent specimen charging. The absence of a conductive coating permits both the acquisition of uncompromised X‐ray spectra, and a dynamic view of impurities as the ice sublimates. The method has enabled us to examine the microstructure and impurities in ice in ways not possible through standard melt chemistry measurements or even through using a SEM to study coated samples. Soluble impurities appeared either as white spots in grain interiors, grain boundaries, and triple junctions, or as filaments in grain boundaries. Inclusions of insoluble impurities have also been observed in natural ice. Thus, we have been able to compare the microstructural location and concentration of impurities in ice from different terrestrial locations. Even when ion chromatography of the melt from two core sections reveals similar levels of impurities, the morphology and location of the impurity aggregates can be quite different. Analysis of impurity type and location can provide clues to the depositional environment and history of the ice. Microsc. Res. Tech. 62:49–61, 2003. © 2003 Wiley‐Liss, Inc.