A TES microcalorimeter EDS-SEM system for rare earth elements

Abstract

FE-SEM with a superconductor transition edge sensor (TES) microcalorimeter EDS is a new system for chemical analysis in electron microprobe. ULTRA55 FE-SEM with TES was used in this study. Four M line characteristic lines are found, in LaB6 spectrum LaMζ at 638, LaMα, β at 840, LaMγ at 1026 and a weak line (M₂N₄ transition) at 1110 eV are detected. The spectra of other REE borides were also assigned the same as La M-lines. For quantitative analysis, we could apply a calibration curve method, using standard specimens of known chemical compositions. Linear calibration curves for a plot of P, Ca, La, Pr, and Nd intensity versus each weight percent were obtained. Although, the relation between the intensity of CeMα, β line and weight percent is nonlinear, it will be caused by X-ray absorption and/or fluorescence excitation, or experimental error. Further study is needed for quantitative analysis of rare earth elements minerals.