A COMBINED MAPPING AND TIME-DEPENDENT INTENSITY CORRECTION APPROACH TO IMPROVE EPMA ANALYSIS OF BEAM-SENSITIVE MATERIALS

摘要

Compositional changes and deterioration of materials under continuous electron bombardment have been long-standing problems in electron microprobe analysis (EPMA). Examples include alkali migration in glass, halogen migration in phosphates, elemental migration in carbonates, and deposition of contaminant hydrocarbons on sample surfaces during electron exposure. Various approaches have been implemented to overcome these problems including shortened analysis time, gentle analytical conditions (low current, large beam diameter), sequential analysis with cooling-off periods, moving the sample during analysis, and use of cryogenic stages. Although all these approaches yield positive net effects they either cannot fully mitigate beam damage or are time-consuming, resulting in loss of spatial resolution or dependence on the availability of nonstandard hardware.