Recent progress in electron probe microanalysis

Abstract

Electron probe microanalysis (EPMA) is a fairly mature analytical technique which has been widely used in the fields of geochemistry and materials science since the early 1960s. The past decade or so has seen dramatic improvements, both theoretical and experimental, in the accuracy with which the concentrations of light elements such as oxygen can be measured by EPMA. This has coincided with a resurgence of interest in mixed-valence oxides which was stimulated by the discovery of high temperature superconductivity, and EPMA is now a vital tool for condensed matter physicists working in this field. Stoichiometric characterization is particularly important in the area of thin films, and a great deal of recent work has been devoted to modifying existing EPMA correction procedures in order to perform analyses of thin film or layered specimens. This article reviews the progress that has been made from a physicist's perspective, paying attention to the levels of accuracy and precision which are now attainable, and to the advantages and disadvantages of EPMA in relation to other analytical techniques.

Low-Voltage Electron-Probe Microanalysis of Fe–Si Compounds Using Soft X-Rays

“…9, seven accelerating voltages were used between 4 and 25 keV). It should be noted that the main assumption of the variable–voltage method is that the underlying X-ray emission model (in this case the XPP model) is error free (Mackenzie, 1993). Therefore, a MAC obtained in this way will in principle be meaningful only when used in conjunction with the same X-ray emission model.…”

Metal-insulator transition in amorphousSi1−xNix:Evidence for Mott’s minimum metallic conductivity

“…In our case, the relative uncertainty of the corresponding Ni:Si ratios was estimated to be better than 2 %, so that the related absolute error of the Ni content should not exceed 0.3 at% in the MIT region. The quantitative result of the EDX analysis however is influenced by a series of effects, in particular this method needs standards and various corrections [58]. Therefore, the systematic errors can amount to several at% so that the differences between the columns of Table III are not surprising.…”

Electron Probe Microanalysis of Thin Films and Multilayers Using the Computer Program XFILM

“…Electron probe microanalysis (EPMA) is an analytical technique widely used for determining the composition of small regions of solid samples (Mackenzie, 1993; Reed, 1993). The technique is based on the measurement of characteristic X-ray intensities emitted by the elements present in the sample when the latter is bombarded with a focused electron beam.…”