Development of Miniaturized Electron Probe X-ray Microanalyzer

Abstract

A miniaturized electron probe X-ray microanalyzer (EPMA) with a small chamber including the electron source and the sample stage was realized using a pyroelectric crystal as an electron source. The EPMA we propose is the smallest reported so far. Performance of the EPMA was evaluated by investigating energy of obtained continuous X-rays and lower detection limits of transition metals (titanium, iron, and nickel). End point energy (Duane-Hunt limit) of continuous X-rays of 45 keV was obtained. However, it is expected that the EPMA can analyze characteristic X-rays with energy less than 20 keV. The EPMA was able to measure titanium, iron, and nickel wires whose projected areas were more than 0.03 mm(2).

Portable pyroelectric electron probe microanalyzer with a spot size of 40 μm

“…We previously realized a portable EPMA using a pyroelectric crystal as an electron source to satisfy the rapidly increasing demand for the on-site elemental analysis of, for example, inclusions in steel products, grains in minerals, and aerosols. 1,2 The portable pyroelectric EPMA mainly consisted of a pyroelectric crystal, a small rotary pump, a Peltier device, a 3 V battery, an X-ray detector, and detachable vacuum joints. Changing the temperature of the pyroelectric crystal in vacuum leads to the accumulation of charges on its surface and the generation of a high electric field between the surface of the pyroelectric crystal and the analyte.…”

Application of pyroelectric crystal and ionic liquid to the production of metal compounds

“…1 After that, several researchers have been working on the application of pyroelectric crystals to X-ray generator with high enery, 2-5 electron and ion beams, 6 ion source for mass spectrometry, 7 and an electron source for electron probe X-ray microanalyzer. 8 In the present study, we applied the high voltage produced with the pyroelectric crystal to a production of metal compounds such as fluoride and sulfide. We selected an ionic liquid containing metal ions as a reactant because ionic liquid has low vapor pressure.…”

“…Pressure of the chamber was set to 2 Pa. During the heating and cooling cycle of the LiTaO 3 crystal, about 50 kV was applied between the LiTaO 3 crystal and the substrate. 8 The precipitates of the substrates were investigated by X-ray photoelectron spectroscopy (JPS-9010TRX, JEOL) with a non-monochromated Mg KD X-ray source. The energy resolution was 1.3 eV measured as a full-width at half maximum (FWHM) of the Ag 3d 5/2 line.…”

Palmtop EPMA by electric battery

“…Then, we presented an EPMA with a palmtop size chamber including the electron source and the sample stage using a LiTaO 3 crystal as an electron source. 4 The EPMA consisted of LiTaO 3 crystal, brass sample stage, rotary pump, vacuum joints, borosilicate glass tube, and copper rods. It took more than 10 minutes for the palmtop EPMA to reach the measurement pressure of 5 Pa.…”