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Developments in Bragg Coherent Diffractive Imaging at the Advanced Photon Source

Event Details

Event Dates: 

Wednesday, July 23, 2014 - 2:00pm

Seminar Location: 

  • JILA X317

Speaker Name(s): 

Mr Nicholas Phillips

Speaker Affiliation(s): 

Australian Research Council Centre of Excellence for Coherent X-Ray Science
Seminar Type/Subject

Scientific Seminar Type: 

  • JILA Public Seminar

Event Details & Abstract: 

Coherent Diffractive Imaging is now an established technique at the Advanced Photon Source (APS) providing new characterization data for a wide variety of biological and materials samples. Recent breakthroughs in CDI at the APS include micro and nanoscale imaging of hydrated biological samples, coupled with simultaneous acquisition of complementary spectroscopic information through ptychograpic CDI. Whole cell images at 20nm spatial resolution have been obtained using these methods with additional elemental information overlaying the phase contrast data. There have also major developments in the image reconstruction algorithms with increased parallelization with CDI in ‘real-time’ a possible in the near-future.

As well as imaging in transmission I have also worked on developing CDI in the Bragg geometry for materials analysis. In this mode it is possible to quantitatively recover deviations of the lattice from perfect crystallinty.  Among the applications we are exploring using this technique is an understanding of the factors affecting the growth of hemozoin crystals a key by-product of the malaria parasite. Limiting the nucleation and size of hemozoin crystals is an essential part of developing new treatments to this widespread disease.

Another major application I will discuss is the use of Bragg CDI combined with ptychography for characterizing spin-orbit coupling in the nano domain structure of doped LaPrCaMnO3 through anti/ferromagnetic phase transitions. Doped manganites have recently become of interest for applications in spintronics and low power devices coupling spin, charge and lattice states/ordering. In the final part of my talk I will discuss some very recent work that we have carried out at the APS on developing Bragg CDI using polychromatic X-ray beams; the successful realization of this technique could enable in-situ studies of strain evolution at the nanoscale in crystalline samples.