For estimations of P-T conditions of igneous and metamorphic rocks, Fe31 in coexisting minerals is either assumed to be zero or is calculated from electron microprobe analyses (EMPA) based upon stoichiometry and charge balance. Geothermobarometers that involve Fe21-Mg21 exchange can be significantly affected by either neglecting Fe31 or using incorrect values. Ratios of Fe31/SFe in garnet and c...

The carbon contents in carburized steels were investigated by electron probe microanalysis (EPMA) for a range of carbon levels in the solid solution less than 1 wt%. This article describes the difficulties encountered with the classic analytical procedure using the k ratio of X-ray intensities and the phi(rhoz) model. Here, a suitable calibration curve method is presented with emphasis on the m...

In ion microprobe analysis the specimen is bombarded with a focussed ion beam a few #m in diameter and the secondary ions produced are accelerated into the entrance slit of a mass spectrometer. An outline of the salient features of the instrument is given here, together with an account of the methods used for quantitative elemental and isotopic analysis. The major part of this paper consists of...

Different modes of SIMS for thin film analysis and the principle of SIMS will be discussed; this will be followed by a discussion of some features related to instrumentation: types of ion sources and their characteristics; ion microprobe versus ion microscope; special modes of SIMS: sputter neutral mass spectrometry (SNMS) and fast atom bombardment. (FAB). The discussion of analytical features ...