7 papers
Crystal Truncation Rods from Miscut Surfaces with Alternating Terminations
Guangxu Ju, Dongwei Xu, Carol Thompson +5
Miscut surfaces of layered crystals can exhibit a stair-like sequence of terraces having periodic variation in their atomic structure. For hexagonal close-packed and related crysta…
Dynamics of Atomic Steps on GaN (0001) during Vapor Phase Epitaxy
Guangxu Ju, Dongwei Xu, Carol Thompson +5
Images of the morphology of GaN (0001) surfaces often show half-unit-cell-height steps separating a sequence of terraces having alternating large and small widths. This can be expl…
In Situ Microbeam Surface X-ray Scattering Reveals Alternating Step Kinetics During Crystal Growth
Guangxu Ju, Dongwei Xu, Carol Thompson +5
The stacking sequence of hexagonal close-packed and related crystals typically results in steps on vicinal {0001} surfaces that have alternating A and B structures with different g…
High-energy coherent X-ray diffraction microscopy of polycrystal grains: first steps towards a multi-scale approach
Siddharth Maddali, Jun-Sang Park, Hemant Sharma +7
We present proof-of-concept imaging measurements of a polycrystalline material that integrate the elements of conventional high-energy X-ray diffraction microscopy with coherent di…
Persistence of Island Arrangements During Layer-by-Layer Growth Revealed Using Coherent X-rays
Guangxu Ju, Dongwei Xu, Matthew J. Highland +7
Understanding surface dynamics during epitaxial film growth is key to growing high quality materials with controllable properties. X-ray photon correlation spectroscopy (XPCS) usin…
Characterization of the X-ray Coherence Properties of an Undulator Beamline at the Advanced Photon Source
Guangxu Ju, Matthew J. Highland, Carol Thompson +5
In anticipation of the increased use of coherent x-ray methods and the need to upgrade beamlines to match improved source quality, we have characterized the coherence properties of…