Exploration and Optimization of Tellurium‐Based Thermoelectrics

Figure 6.1 (a) LEO 1530 SEM (b) EDX Process
Samples are attached to conductive carbon tape in < 10 mg powders or single crystals and
attached to an aluminium sample holder. The data is collected as relative intensity on the y‐axis and
energy (in eV) on the x‐axis as displayed in Figure 6.2 (a). Spectra are collected for each sample in full area
scans, partial area scans or point scans, each having its own advantage. For example, a full area scan
(overall) will give the user an understanding of the spectra for hundreds of crystals at once whilst a point
scan will read a token pixel or two from the screen. While the area scans capture other elements such
as pieces of glass or carbon tape in the sample, the point scans may not represent the majority, should
the crystallite belong to an obscure phase or be resting on another crystal; the energy is high enough to
penetrate thin materials. Several scans are therefore collected for a more comprehensive data set.
Results are collected as weight or atomic percent (Figure 6.2 (b)) and can be assumed to be 1 %, while
the technique can detect any elements having nuclei around the size of carbon or larger.
Figure 6.2 Sample EDX (a) Spectrum (b) Results
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