Portable analyzer using pyroelectric crystal

Abstract

We have recently realized an electron probe microanalyzer (EPMA) and cathodoluminescence (CL) spectrometer with a palm-top size chamber including the electron source and the sample stage using a pyroelectric crystal as the electron source. In the present study, we carried out microanalysis and elemental mapping using the portable EPMA and CL spectrometer. As for the portable EPMA, the electron beam bombarded a sample and the wall of the stainless steel chamber due to using a LiTaO3 single crystal with a cuboidal shape. The electron beam was focused on the sample by setting a metal needle on the pyroelectric crystal and covering the needle holder with an insulating material. The spot size of the focused electron beam was 300 μm. We succeeded in elemental analysis in micro-scale region using the focused electron beam. The portable EPMA can also detect light elements such as Mg, Al and Si by introducing the X-ray detector into sample chamber. The portable CL spectrometer can detect ppm order of rare-earth elements in a mineral ore. The portable CL spectrometer can also perform an elemental mapping of rare-earth elements by capturing a CL image with CMOS camera.