Powder
X-Ray Diffraction Laboratory
This laboratory consists of one major instrument, a Scintag XDS-2000 diffractometer, and
many users. This is one of our most heavily used instruments, with annual usage
rates consistently greater than 125% and with on average over 30 users on the license at
any one time. While most of the usage has been from within our own department
researchers from the departments of Textiles, Electrical Engineering, Mechanical
Engineering, Civil Engineering, Chemistry, Land, Air and Water Resources, Geology, Vet/Med
and others have made this a truly inter-departmental instrument.
This diffractometer was purchased in 1993 and since then has become an indispensable tool in our teaching and research programs. In 1999, after several years acquiring experience with this instrument and building up a user base it went on recharge. At this point it is a self-supporting instrument, and with such heavy usage, the rates are very reasonable.
If you are interested in using this diffractometer, getting training to use it your self, or if you have work you'd like for us to do for you please contact the instrument's manager.
Scintag XDS 2000 Diffractometer
The Scintag XDS 2000 is a
state-of-the-art x-ray diffractometer, featuring a theta-3theta goniometer, computer
control of collection of data and a host of programs for manipulating and analyzing the
data. The goniometer features independent control of incident (omega) and diffracted
(theta) angles plus specimen rotation (phi). Its 2-theta range is -3 to 140 degrees
with 0.01 degree accuracy while phi can be rotated from plus and minus 360 degrees. A 2.2
kW line-focus copper tube is normally used but a 1.7 kW chromium tube is available for
those who need it. The detector is a solid-state intrinsic Germanium detector whose output
is filtered to provide the k-beta discrimination which, on older systems, is usually
handled by a monochrometer. The combination of a bright x-ray source and the absence of a
monochrometer make if possible to perform routine "qualitative" scans in as
little as 4-6 minutes and "quantitative" scans in typically 30 minutes. For more
details on this instrument's specifications see the diffractometer page.
DMS
We are running both the VMS and Windows NT versions of Scintag's software. Either version
can be used to operate the diffractometer and analyze the results. The analysis package
that comes with this software provides programs for background and k-alpha-2 stripping, a
peak-finder program, a search-match program which attempts to match powder files with your
data, peak profile fitting, several methods of indexing peaks, particle size measurements
using the Warren-Averbach and Scherrer methods, analysis of residual stress, percent
crystallinity, percent retained austenite, I/Ic quantitative analysis using the matrix
flushing technique and other programs and utilities.
JCPDS
In addition to Scintag's software we have the complete JCPDS powder diffraction database
on CD-ROM. It is available over the network and can be accessed by any computer in the
department (assuming you have downloaded and installed the PCPDFWIN program).
Contact the laboratory's manager if you'd like to
find out how to do this.
Training
Anyone interested in using this instrument will first have to:
To take EH&S's course simply contact them to reserve a spot in the next class they offer. Make sure you sign up for the "Analytical X-Ray Safety Course" and not the "Diagnostic X-Ray Safety Course". After you take their course you must submit a statement of experience form and the instrument's manager will submit an amendment to the machine's license. You will then be issued personal dosimetry. Now you are eligible for training on the operation of the Scintag X-ray diffractometer. This training normally takes one morning to complete and it is only given on a one-on-one basis to ensure that you become proficient and self-reliant very quickly. Once you have completed this training you be able to schedule time on the instrument at any time. To schedule time on the x-ray diffractometer contact the instrument's manager via phone, in person or by email to reserve a time slot. For more details on the training requirements and the training procedure see the diffractometer page.
Division of Materials Science
If you have any questions or comments regarding this web site please contact the webmaster.
Updated on June 25, 2001
Department of Chemical Engineering and Materials Science
University of California, Davis
Davis, CA 95616
USA
Phone: 530/752-0400
Web: www.chms.ucdavis.edu