Polydisperse NiTi nanoparticles investigated by X-ray standing waves and electron microscopy—A comparative study

• X-ray standing waves are suitable for the analysis of polydisperse nanoparticles.
• XSW scans capture a large number of particles at once, improving the statistics.
• XSW combined with electron microscopy provide a comprehensive particle analysis.

A polydisperse mixture of nickel–titanium nanoparticles generated by femtosecond-laser ablation was investigated by the application of different analytical methods in order to characterize the distribution of particle sizes. Images obtained with scanning and transmission electron microscopy and intensity curves of fluorescence excited by X-ray standing waves (XSW) were evaluated and the resulting distributions were plotted in several histograms. Based on the differences found in the results, the possibilities, limitations and appropriate criteria of application of the respective technique are discussed. The principles of the XSW technique and the evaluation procedure are explained in more detail. The respective analytical methods were compared in terms of spatial resolution, information content, the risk of artifacts, the statistics of the evaluation and the availability of experimental facilities.