Thursday, February 1, 2007Volume 7, Issue 1
New X-Ray Diffraction Equipment is Fast and Focused
A new tool for studying crystalline materials at the atomic level has arrived on campus and is housed in the Materials Characterization Lab at Hosler Building. The first of its kind on campus, the Microfocus X-Ray Diffractometer has several unique abilities, according to Mark Angelone, the lab manager in charge of the new instrument.
"This instrument is unique in that it can do very small samples in a variety of forms," he says. Compared to other x-ray diffraction tools on campus that look at samples in the 10-30mm size range and average the results over the entire field, the Microfocus X-Ray Diffractometer can isolate an area less than 100 microns wide. Sample size can be as small as a few micrograms, which is especially important for researchers whose process produces very small amounts of material over a long time. The instrument can also look at very small areas of larger samples.
Mark Angelone studies the image created by the new Microfocus X-Ray Diffractometer in Hosler Building.
Another unique feature of this instrument is that it is very, very fast, Angelone explains. Other x-ray diffraction equipment on campus can take from 30 minutes to an hour to collect a decent pattern. This is due to one dimensional step-by-step sequential scanning of the x-ray scattering. With the new equipment, the entire black surface of the detector that is visible in the photo senses the scattering simultaneously in two dimensions.
"We can collect very fast patterns," says Angelone. "That's important, not only for data collection efficiency, but also because we're doing time-resolved experiments where a sample is actually changing with time. We can get a pattern every 30 seconds over the course of a temperature run or humidity run in an environmental chamber. So time is more than a convenience issue in a lot of cases, and this machine is the first one on campus to address it."
Image of the scattering pattern for corundum (alpha- aluminum oxide). The scattered radiation is Cu Ka.
The instrument, which was commissioned in early November, is still not widely known on campus, Angelone remarks. But several groups have already jumped at the chance to utilize its unique features. "Before they had this instrument, they had to go to the synchrotron at Brookhaven or out at APS and do their experiments there," he says. "There may still be a requirement for synchrotron radiation, but this instrument can pre-screen samples to reduce the amount of work that has to go to the synchrotron or provide the data outright."
Researchers already utilizing the tool come from a range of disciplines, from geoscientists studying weathering processes in certain minerals to food scientists analyzing small extracts of starches. Angelone is impressed by the instrument and looking to add new features in the coming months. "I have people bringing me samples stuck on the head of a pin saying, 'That's all I've got'."
The Materials Characterization Lab (MCL) is a fully staffed analytical laboratory, which serves the materials community at Penn State offering a range of state-of-the-art analytical techniques and support services. MCL is part of the Materials Research Institute. Mark Angelone can be reached at msa3@psu.edu or 883-9350.
