New method makes material testing more reliable by combining multiple analysis tools
Researchers developed a more accurate way to interpret test results for tungsten-nitrogen compounds by merging data from six different analytical techniques. The finding suggests that relying on a single testing method can miss critical information about material properties, a lesson with broad implications for quality control and materials development in manufacturing.
Originaltitel: Enhancing the reliability of XPS spectra interpretation by microstructure analysis and self-consistent peak modelling: The case of W1-xNx (0 = x = 0.65)
<p>The reliability of XPS spectra interpretation of heterogeneous materials exhibiting compositionally-driven phase transformations is shown to improve by a comprehensive sample analysis including characterization of microstructure, elemental composition, impurity level, and phase constitution. This approach is demonstrated here for a series of W1-xNx films with N content varying in the range 0 &lt;= x &lt;= 0.65, which results in a complex evolution of W 4f spectra. The reliability of peak models is further enhanced by performing self-consistent XPS analysis from all major core level spectra (W 4f, N 1s, O 1s, and C 1s) in liaison with XRD (for crystalline phase content, lattice parameters, preferred orientation), ToF-ERDA (elemental composition, impurity levels), SEM and TEM (micro-and nano-structural analysis), and SAED (crystalline content down to the nm-level). It is thus found that a phase transformation occurs as x increases from bcc alpha-W(N) with x = 0.06 to bcc alpha-W(N) + cubic (1-WyN (0.08 less than or similar to x less than or similar to 0.27), cubic (1-WyN + hexagonal W2N3 (0.36 less than or similar to x less than or similar to 0.56), and finally to cubic (1-WyN + amorphous WN2 (0.62 less than or similar to x less than or similar to 0.65). The comparison of spectra recorded before and after Ar+ etching reveals that sensitivity to sputter damage varies greatly between different phases. This integrated methodology is particularly valuable for transition metal nitrides, carbides, and related compounds exhibiting continuous structural evolution with overlapping XPS signatures.</p>