Poly: an algorithm for spot-wise phase identification in polymorphic nanomaterials
What is it about?
This manuscript describes a new phase identification algorithm called poly intended for spotty selected-area electron diffraction patterns collected from polymorphic nanomaterials. We have developed this new approach to determine the predominant high-pressure phases produced in laser-shock-affected regions of Silicon. In this study, we find that extreme femtosecond laser fluences ( > 40 J/cm2 ) lead to the formation of the novel t32-Si and t32*-Si phases and study their relaxation in time.
Why is it important?
Phase identification in polymorphic nanomaterials is a challenging task. Previously, it has been performed by analyzing selected-area electron diffraction (SAED) patterns from laser-shock-affected regions of Si samples, revealing high-pressure phases such as t32-Si and t32-Si. However, the analysis was complicated by pattern overlap from multiple crystallites within the selected area, with many diffraction spots matching multiple potential phases. This new algorithm reduces ambiguity and enables spot-wise phase identification with greater accuracy.