Structural characterization of ZrCu thin films by ePDF correlated with morphological and analytical data

ZrCu thin films were grown by DC magnetron sputtering across the full composition range to investigate the amorphization degree by pair distribution function obtained by electron diffraction. The length of structural coherence analysis, obtained from the electron pair distribution function and normalized by bond distances, proved to be a reliable parameter for quantifying amorphization. These analyses showed that alloys containing 20–50 at.% Zr exhibited the highest range of amorphization degree, with Zr38.2 presenting the strongest amorphous character. Morphological analysis using high-resolution transmission electron microscopy images and atomic force microscopy images reveals phase segregation in Zr22.1 and Zr79.5. Oxidation analyses conducted by electron energy loss spectroscopy and X-ray photon spectroscopy revealed that Zr-rich alloys experienced stronger oxidation, primarily due to the formation of a passivation layer rather than bulk incorporation. These findings provide a detailed correlation between structural and morphological features, validating theoretical predictions for the optimal amorphous range and contributing to the design of ZrCu-based metallic glasses.