The Bruker GADDS now has a Cobalt anode to provide low background 2D XRD data of Fe or Co containing samples while mitigating the fluorescence issues associated with a Cu target. Also, an Oxford Cryosystems Cryostream 700 has been outfitted to the Bruker GADDS system to provide variable temperature XRD down to -80º C. Contact Dr. Charles Settens for training.
The Center for Materials Science and Engineering has committed to supporting lab-based Small Angle X-ray Scattering (SAXS) in the X-ray Diffraction Shared Experimental Facility. The Institute for Soldier Nanotechnologies SAXS system has been moved to the CMSE X-ray facility and is currently being upgraded by CMSE to support research programs that would benefit from an X-ray nanoprobe sensitive to size scales from 0.5 – 200 nm. The planned upgrades include a vacuum compatible DECTRIS PILATUS 300K detector, automated sample to detector distance positioning, tunable scatterless collimation slits, a HUBER two circle segment for GI-SAXS stage - all controlled by spec. Contact Dr. Charles Settens for training on the SAXS system.
In addition to single crystal structure refinement, the Chemistry Department’s Diffraction Facility now offers transmission-mode powder diffraction at temperatures from 100K to 500K. Transmission mode diffraction gives rise to high-quality powder patterns from minute amounts of sample (only ca. 2 cubic millimeters of tightly packed powder are needed) and the variable temperature setup, which is unique on MIT campus, allows the examination of many phase transitions. In addition, the user has the choice of copper and molybdenum radiation (Mo radiation reduces fluorescence in samples containing Co or Fe). The quality of the powder data collected in the facility is generally high and on several occasion was good enough for Rietveld refinement. For further information contact Dr. Peter Mueller or see here: http://web.mit.edu/x-ray/powder.html.
This instrument is currently working. Due to low usage and limited interest, training for this system will be one-on-one and must be pre-arranged with staff. Please send an email expressing your interest and the nature of your samples to one of our staff.
If you would like to visit the old website, it has been moved to prism.mit.edu/xray/oldsite.
The RU-300 instrument has received an upgrade! A new chromium anode has been installed. X-rays from chromium have a longer wavelength than those from copper, which eliminates the problems of absorption and fluorescence from materials containing iron and cobalt. However, you can expect your diffraction peaks to show up at higher values of 2Theta. In addition, you may need to scan for a longer time to achieve the same signal to noise ratio. For data analysis in HighScore Plus, you will want to set the X-ray wavelength to chromium under the Document Settings window.
Scott Speakman has left MIT for a position as Principal Scientist at PANalytical. Users should now contact Charles Settens (firstname.lastname@example.org) for technical help in the X-ray lab. Please contact Susan Dalton (email@example.com) for administrative help. You may contact Scott Speakman at his new email address, firstname.lastname@example.org.