K. A. Seu
Lawrence Berkeley National Laboratory
Speckle patternFourier transformOpticsPhysicsCoherent diffraction imagingPhase transitionSaturation (magnetic)HolographyScatteringMaterials scienceMetrologyDiffractionCondensed matter physicsNanophotonicsPerpendicular anisotropyMagnetic filmsMagnetizationMagnetic anisotropyPhase (matter)Reflection (mathematics)PtychographyHeterojunctionSpin-½Anisotropy
6Publications
3H-index
166Citations
Publications 3
Newest
#1Sujoy Roy (LBNL: Lawrence Berkeley National Laboratory)H-Index: 16
#2Daniel Parks (LBNL: Lawrence Berkeley National Laboratory)H-Index: 5
Last. S. D. Kevan (UO: University of Oregon)H-Index: 13
view all 9 authors...
Many X-ray imaging techniques require transmission geometries, which place severe restrictions on the samples being imaged. Here, a reflection geometry lensless X-ray imaging method is demonstrated. This technique may allow single-shot imaging of surfaces and films such as organic photovoltaic materials and field-effect transistor devices, or Bragg planes in a single crystal.
60 CitationsSource
#1K. A. Seu (LBNL: Lawrence Berkeley National Laboratory)H-Index: 3
#2Sujoy Roy (LBNL: Lawrence Berkeley National Laboratory)H-Index: 16
Last. Stephen D. Kevan (UO: University of Oregon)H-Index: 40
view all 6 authors...
Using coherent soft x-ray scattering we have measured slow magnetization fluctuations in an Au/Co/Au heterostructure near a thermally driven spin-reorientation phase transition. The intermediate scattering function is well described by a stretched exponential, suggesting cooperative motion through the transition. The decay times were found to exhibit a pronounced maximum as a function of temperature. We argue that the transition proceeds through a cone phase in which the local magnetization evol...
15 CitationsSource
#1K. A. Seu (LBNL: Lawrence Berkeley National Laboratory)H-Index: 3
#2R. Su (UO: University of Oregon)H-Index: 2
Last. Stephen D. Kevan (UO: University of Oregon)H-Index: 40
view all 7 authors...
We report soft x-ray speckle metrology measurements of microscopic return point and complementary point memory in Co/Pd magnetic films having perpendicular anisotropy. We observe that the domains assemble into a common labyrinth phase with a period that varies by nearly a factor of two between initial reversal and fields near saturation. Unlike previous studies of similar systems, the ability of the film to reproduce its domain structure after magnetic cycling through saturation varies from loop...
6 CitationsSource