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Materials Characterization

Scanning Electron Microscopy (SEM)

Scanning Electron Microscopy uses a focused electron beam to scan a solid sample from the optical to nanoscale range. Secondary electrons are generated in the sample and collected to create a map of the secondary emissions. Since the intensity of secondary emission is dependent on local morphology, the area map is a magnified image of the sample. Spatial resolution is smaller than a nanometer for some instruments, but 3 nm is typical for most.

Faculty Experts: 
Anderson, Julie
Auker, Wes

Raman / PL / AFM

Raman spectroscopy is a light scattering analytical technique used to probe both organic and inorganic materials. The information from Raman spectroscopy can be used to identify chemistry, molecular structure, effects of bonding, stress/strain, and environment effects (temperature/humidity). A very wide variety of samples can be measured with this technique, including solids, liquids and gases. This is also a non-destructive technique. The scale at which information can be obtained also varies from 10s of nanometers to a few millimeters.

Faculty Experts: 
Wetherington, Maxwell

Particle Sizing

Particle size and shape are two of the most important physical properties of particulate samples. Even small differences can significantly affect material properties such as chemical reactivity, bioavailability, dissolution and crystallization rates, stability in suspension, texture of the material, flow ability and handling, packing density and porosity, to name a few.

Faculty Experts: 
Bazilevskaya, Katya

Optical Profilometry

Optical profilometry is a rapid, nondestructive, and noncontact surface metrology technique. An optical profiler is a type of microscope in which light from a lamp is split into two paths by a beam splitter. One path directs the light onto the surface under test, the other path directs the light to a reference mirror. Reflections from the two surface are recombined and projected onto an array detector. When the path difference between the recombined beams is on the order of a few wavelengths of light or less interference can occur.

Faculty Experts: 
Tighe, Tim

Nanoindentation

The nanoindenter is designed to measure the mechanical properties of surfaces on a submicroscopic scale. The indenter takes a small diamond, which is shaped as either a pyramid or a sphere, and pushes the diamond tip into the surface of the material being tested. The depth of indentation can range from a couple of hundred nanometers to a maximum of 4 microns. By measuring the force required to push the diamond tip into the material compared to the depth of the indentation, the instrument can determine the hardness of the sample.

Faculty Experts: 
Tighe, Tim

EPMA - Electron Probe Micro Analyzer for Materials & Geosciences

Electron Probe MicroAnalysis (EPMA) is a non-destructive technique to determine chemical composition of small amounts of solid materials. A focused beam of high-energy electrons hits the sample and generates characteristic x-rays corresponding to the elements present in the material. The beam current is typically between 10-100nA, much more intense than SEM. This produces a higher count rate, thus improving precision, accuracy and detection limits (~100s ppm).

Faculty Experts: 
Crispin, Katherine

Electrical Characterization

Dielectric Properties Lab

Electrical characterization is performed using a variety of temperature chambers, LCR meters, impedance analyzers, pA meters, DMMs, charge converters, lock-in amplifiers, dynamic signal analyzers, voltage amplifiers, and sample fixturing for bulks, films, and leaded samples.

Many measurements are entirely automated with the GADD measurement program. GADD takes directions in the form of a short user generated script file (text file) and uses those directions to control the measurement hardware to collect data your way.

Faculty Experts: 
Long, Jeffrey

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