Distinguishing space groups by electron channelling: centrosymmetric full-Heusler or non-centrosymmetric half-Heusler?

X-ray emission under electron-channelling conditions is used to distinguish between a non-centrosymmetric half-Heusler and a centrosymmetric full-Heusler crystal. For TiCoSn the space-group determination based on a Rietveld refinement procedure became challenging for increasing Co content (x > 0.2), while electron channelling proved successful for higher Co content (x = 0.

Bloch wave symmetries in electron diffraction: applications to Friedels law, Gjonnes-Moodie lines and refraction at interfaces.

We classify the point symmetries at the different points in the Brillouin zone for the 17 two-dimensional space groups and the symmetries of the Bloch waves for the 10 two-dimensional crystallographic point groups. Simple examples involving breakdown of Friedels law, Gjonnes-Moodie lines, and reflection and refraction at interfaces are presented.

A specimen preparation technique for plane-view studies of surfaces using transmission electron microscopy.

A method for preparing plane-view transmission electron microscope (TEM) samples is presented. With this inclined pseudo-plane-view technique, the undisturbed surface of the sample can be studied in plane view. Thus, nanostructures on the surface of a substrate can be studied with TEM in much the same way as with scanning electron microscopy (SEM), but in transmission at a much higher spatial resolution and with the opportunity of performing nanoscale diffraction.

Comparison of the electronic structure of a thermoelectric skutterudite before and after adding rattlers: an electron energy loss study.

Skutterudites, with rattler atoms introduced in voids in the crystal unit cell, are promising thermoelectric materials. We modify the binary skutterudite with atomic content Co(8)P(24) in the cubic crystal unit cell by adding La as rattlers in all available voids and replacing Co by Fe to maintain charge balance, resulting in La(2)Fe(8)P(24). The intention is to leave the electronic structure unaltered while decreasing the thermal conductivity due to the presence of the rattlers.

A quantitative study of valence electron transfer in the skutterudite compound CoP(3) by combining x-ray induced Auger and photoelectron spectroscopy.

We use the sum of the ionization and Auger energy, the so-called Auger parameter, measured from the x-ray photoelectron spectrum, to study the valence electron distribution in the skutterudite CoP(3). The electron transfer between Co and P was estimated using models relating changes in Auger parameter values to charge transfer. It was found that each P atom gains 0.