Abstract
In situ total scattering measurements are increasingly utilized to follow atomic and nanoscale structural details of phase transitions and other transient processes in materials. This contribution presents an automated method and associated tool set to analyze series of diffraction and pair distribution function data with a linear combination of end-member states. It is demonstrated that the combinatorial appraisal of transition states (CATS) software tracks phase changes, relative phase fractions and length scales of interest in experimental data series. It is further demonstrated, using a series of local structure data simulations, that the misfit of such a model can reveal details of phase aggregation and growth related to the pair distribution function's sensitivity to interphase correlations. CATS may be applied to quantitative evaluation of many transient processes, including amorphous-to-crystalline phase transitions, the evolution of solid-solution behaviors, the precipitation and growth of aggregates, and other atomic to nanoscale details of crystallization and phase transformation phenomena.A method and software tool are introduced to fit a series of pair distribution function data through a phase transition or to detect and track a specific structural feature of interest using a linear combination of two end-member states. The misfit between the model combination and the data can reveal underlying details regarding the nature and length scale of intermediate structures.
Original language | English |
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Pages (from-to) | 1744-1753 |
Number of pages | 10 |
Journal | Journal of Applied Crystallography |
Volume | 50 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2017 |
Funding
This work was supported through the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Early Career Research Program award KC040602. Research conducted on the NOMAD beamline at ORNL’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Sciences, US Department of Energy. The creation of the A(B)CC datasets was supported by the US Department of Energy (DOE), Office of Science (SC), Office of Basic Energy Sciences (BES), Chemical Sciences, Geosciences, and Biosciences Division.
Keywords
- growth
- hierarchical structures
- interfaces
- pair distribution function (PDF)
- phase transitions
- total scattering