Welcome to the Materials Analysis and Research
The Materials Analysis and Research Laboratory (MARL) is one of the core
instrumentation facilities administered by Iowa State University's Office of
Biotechnology. That office is part of the Office of the Vice President for
Research and Economic Development.
We are located in rooms 23 through 68 in the basement level of Town Engineering Building at the northwest corner of
the Iowa State University campus in Ames, Iowa (campus
The laboratory includes equipment for:
- Scanning Electron Microscopy (SEM)
- Energy-dispersive x-ray spectroscopy (EDS)
- X-ray Diffraction (XRD)
- X-ray Fluorescence (XRF)
- Thermal Analysis (DTA, TGA)
Here are some links to the rest of the site:
- Fees for Services
- MARL WWW site (the detailed lab web pages)
- MARL ftp site (a repository of user files for
downloading. Sensitive files are stored in a password-protected area.)
Note: some browsers and sites may have problems, on their end, that prevent accessing
these files. First, try refreshing the page. Click here
for detailed explanations and
- Thermal Analysis results
(including runs in progress)
- Interesting files
(this subdirectory has a number of interesting pictures)
- Utilities (this
directory includes several utilities including the PCI Viewer for images.)
- Pixera example files
(a collection of images taken with our Pixera CCD camera. The x-resolution makes up the
last part of the file name.)
- Equipment schedules Users may view equipment schedules
prior to requesting appointments.
MARL has upgraded equipment for microscopy, thermal analysis, and
x-ray fluorescence. Funding was provided by the Iowa State Regents Innovation
Fund, the Office of Biotechnology, the College of Engineering, and MARL.
The FEI Quanta SEM has been upgraded with the addition of a heating
stage. It offers dynamic, in-situ analysis of samples over a temperature range
from ambient up to 1000C. Software allows for creation of movies showing changes
The thermogravimetric analyzer has been replaced with a TA Instruments
Discovery TGA system. It is used for measuring weight changes as samples are
heated in a controlled atmosphere from ambient up to 1200C. It is a fully
automated with a 25-position auto-sampler and a gas-switching/blending module.
It also offers automated sample pan piercing while in the selected atmosphere.
Off-line analysis software is available for installation on an unlimited number of user
For x-ray fluorescence, a new, automated sample fusion system from
PANalytical has been installed. It permits unattended fusion of one or two
samples at temperatures up to 1200C. It also provides in-furnace pouring which
allows for the crucible and casting dish to be at the same temperature.
MARL has updated the Oxford Instruments Aztec EDS system to version
2.1. It adds capabilities for Auto-Phase in conjunction with x-ray mapping.
There is a slight change in appearance of other functions, but not as marked as
the upgrade from version 1.0 to 2.0.
The FEI SEM has been upgraded with beam deceleration and a concentric
backscattered (CBS) electron detector. Beam deceleration allows the use of lower
voltages (a few hundred volts) while maintaining image quality. The CBS detector
is more sensitive at lower voltages and will replace our split-ring BSE detector
for many applications. The concentric rings allow for choosing the energy of the
backscattered electrons that are detected especially when using beam
MARL has purchased and installed an Oxford Instruments Aztec EDS system on the
Quanta FEG 250 SEM. This system has an 80 mm2 detector to allow x-ray
analysis under lower beam currents (smaller spot sizes) than is normally
possible. The system also includes Oxford's Tru-Map software which allows for
background removal and deconvolution of overlapping elements.
November 1, 2011
MARL has instituted a new
sample submission form. Users submitting samples for
analysis requiring staff assistance will need to submit a form with each set of samples. Users doing work
on their own will only need to submit the form once unless their account number
Users are encouraged to save the form on
their own computer so they can fill out and save the basic information. They can
update the other information as it changes.
MARL has purchased and installed an FEI Quanta-250 field-emission with high
vacuum, variable pressure, and extended vacuum (i.e., environmental) modes of
operation. The FEI's stated resolution is just over 1 nm which is a three-fold
improvement over MARL's previous JEOL and Hitachi SEMs.
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