1 BROOKHAVEN SCIENCE ASSOCIATES

End-station for Soft X-ray Diffraction Microscopy

Stuart Wilkins CMPMSD, BNL

2 BROOKHAVEN SCIENCE ASSOCIATES

Science Outlook

To date soft x-rays have been successfully used to study bulk phenomena in strongly correlated electron materials. Measurements have been performed on charge stripes in cuprates, orbital order in manganites, magnetic spin ordering.

But SCES are often not homogeneous!

• What (sample) properties effect phase transitions?

• How sensitive is phase segregation to doping, strain and reduced dimensionality (thin films)?

• What interplay is there between macroscopic properties of domains and the competing order parameters?

• Are the various types of electronic order of SCES homogeneous. What is the role of inhomogineities?

3 BROOKHAVEN SCIENCE ASSOCIATES

Science

• Examples• Manganites

– An open questions is that of phase segregation into AF and FM regions which has a profound consequences to the resistivity and CMR effect and indeed the whole phase diagram.

– Direct imaging of spin, charge and orbital domains in strongly correlated materials. E.g. Pr(1-x)CaxMnO3 which shows different (bulk) correlation lengths which has fundamental implications to the Goodenough model for OO in manganites.

• Cuprates

– Display superconductivity around the bubble in the phase diagram and can display either static or dynamic charge and spin stripes. This relationship is very “hotly” debated within CMP. Open questions exist as to whether the strip order is homogeneous? Connect STM with neutron scattering?

4 BROOKHAVEN SCIENCE ASSOCIATES

Our Endstation

5 BROOKHAVEN SCIENCE ASSOCIATES

Where are we now?

• This project is currently in the conceptual design phase.• Conceptual Design Review Oct 2007• Final Design Feb 2008• Commissioning on NSLS April 2010• Ready to go on first beam of NSLS-II

• We would actively seek to become a Partner User of a NSLS beamline.

6 BROOKHAVEN SCIENCE ASSOCIATES

Requirements from Beamline

• High brightness soft x-rays. 500 eV to 2 keV

• Beam characteristics for use with zone plate optics.

• High degree of coherence.

• Variable polarization.• RXS requires incident and exit polarization control.• Desirable would be the ability to control very fast the

polarization to form a polarimitary type measurement.

• Very high stability.