Group Meeting 2001 July 5 Thursday

I. Announcements

1. Scott’s NRL proposal received an “A”!
2. Grant for X23B upgrade—all optics will be replaced, mirrors, crystals, motors.  Advantages:
   • Will increase energy range…mirrors will be longer and wider and critical angle will be larger so will be able to go up to 35 keV.
   • Will give us substantially greater flux; an increase of a factor of 10 or 20 is expected.
   • Energy resolution will improve by a factor of 3 or 4.  Useful for XANES.
   • Will also allow us to go to much lower energies, <=2 keV.
   • Our group will get 15% of the beamtime for the next 5 years.
3. Scanning Tunneling Microscopy.  This fall, a new faculty member will be coming to Hunter to use this technique to move biological molecules around.

II. Last run report

1. Photovoltaics—forgot to change the gas inside the hutch to Argonne—noisy, low It.  Scott reran the Selenium edge
2. Manganese temp series complete.
3. Titanate powders were a success.
4. Battery cells (Titanate powder (cathode) on Al foil, with electrolyte in between.  Li foil on top) were too thick.  The hypothesis is that the window (low Z material) absorbed too much.
5. Quantum dots were not done because they need to run in fluorescence for very long scans.  Scott did try fluorescence on sandwich samples.  Prof Nilsen checked in with Scott at the end run to collect the samples.  It turns out that the germanium layer was about 50 microns from one surface of the sample but 2 mm from the other side, and Scott had placed the 2 mm away side in the beam.  Even with filters, Scott feels the scan was getting overwhelmed by Si fluorescence.  Had we known and flipped sample around we may have been able to see some kind of edge.  For August:  shiny side out!

III.Next run scheduled for August 23-30.

IV.EXAFS workshop

• Ifeffit,  Macros

V.Progress Reports

1. Hershie—Vanadates.  Fits are reasonably stable but parameters are indicating that the fit is off from the model—shifted.
2. Mike Benjamin—Fe fits.  Reasonably good fit—rfactor very low but reduced chi square is a bit too high.
3. Mike Rivlin—plotting correlated parameters for Mn.
4. Jackson.
5. Theanne—photovoltaics.  Francesconi sample analysis on hold—waiting for a proposed structure for the Sm.
6. Roman—300K for Mn, then one more temp til done.
7. Scott—Sent in PRL revision, working on dissertation.   Lab hours will be limited for the rest of the summer.  Scott will generally be in on Mondays, not on Tuesdays, and will have short, varied hours between Wed and Fri.
8. Mark—picked up the Ni fit from David.  Reduced chi square down to 5.

VI.  Next meeting:  Thursday, July 19 at 11:30.  Jason nominated to bring bagels and fruit.