X‐ray spectroscopy and quantification of an AlCuLi quasi‐crystal: A step forward for combination of reflection zone plate and crystal spectrometers

Abstract

We present the analysis of an AlCuLi quasi‐crystal on an electron probe microanalyser equipped with spectrometers working both in the soft and ultra‐soft x‐ray ranges. This original combination enables obtaining the Li Kα and Al L2,3 emissions with a reflection plate spectrometer and the Al Kβ and Cu Lα emissions with a curved‐crystal spectrometer. All these emissions are emission bands, sensitive to the chemical state of the emitting element. From the observation of the valence band shapes, it is confirmed that the electronic structure of the quasi‐crystal is quite different from that of the corresponding pure metals. From the measured intensities, quantification is performed using the PAP model. The weight fractions calculated from the ultra‐soft x‐ray emission intensities are very dependent on the chosen database of mass attenuation coefficients. Comparison with fractions calculated with small uncertainty in the soft x‐ray range enables choosing which databases are the most relevant for the ultra‐soft x‐ray range. Both quantifications performed from ultra‐soft and soft x‐ray emissions are compatible, leading to the Al60Cu24Li16 weight concentration of the quasi‐crystal.