Numerous analytical techniques for the study of solid materials surfaces and failure analysis have been developed in the last few years. Increasing importance is placed on the physical and chemical characteristics in the surface and near surface region of materials. Fields as diverse as biology and aerospace have been affected by the need to identify surface chemistry of critical materials. A brief overview of some of the techniques currently available for surface characterization will be presented along with examples of problem solving and research applications.
A multitude of publications are available which itemize the various techniques that can be applied to the study of materials. The methods are too numerous to list and discuss in the scope of this document. Because each available method of study has unique strengths and weaknesses, a clear knowledge of these characteristics can often reduce the time necessary to arrive at a solution to a failure problem or the answer to a materials design question. In this document, several analysis types will be discussed with sufficient detail to highlight their relative usefulness in failure analysis and materials characterization.
MRL's primary focus is to respond in a timely manner to solve our clients' problems. A specialist is always available to discuss your objectives. Since we routinely operate around the clock, you can expect rapid turnaround without the surcharges most other laboratories impose.
| AES/SAM - Auger Electron Spectroscopy Useful for high spatial resolution studies and for elemental mapping or line scan studies. Allows for study of 1-10nm layers in areas as small as 50nm on conductive materials and in the 100nm range for most materials. Provides information about elemental composition and spatial or depth distribution. Can be used to profile as deep as 10µm below a surface. All elements except H and He can be detected. | Metallography Describes all variations of the sample preparation procedure which generally starts with cutting a sample cross section, mounting in epoxy or bakelite, grinding with SiC or diamond, polishing with diamond and/or alumina, etching and photographing. The term includes all materials and composites (not just metals), many variations of the procedure depending on the specific situation and all kinds of documentation techniques from photomacrography/ microscopy to electron microscopy/microanalysis. |
| XPS - X-ray Photoelectron Spectroscopy Provides elemental and chemical information about materials surfaces in layers from 0.5nm to 10nm. Performed on the latest instrumentation allowing analysis using various x-ray excitation sources: in small spot sizes; by depth profiling; for ultra-high resolution (using monochromator); for angle-dependent studies, etc. High count rates allow for rapid analyses and speedy turn-around. All elements except H and He can be detected. | SEM - Scanning Electron Microscopy Supplies visual images of materials surfaces. Micrographs in the magnification range of 10X to 200,000X can be obtained. Samples can also be viewed using backscattered electrons for image production to show limited elemental distribution data. The SEM does not suffer from the light microscope problems of light reflecting off at odd angles and being lost from view. |
| ISS - Ion Scattering Spectroscopy The most surface sensitive of the various surface methods. Performed on hemispherical or cylindrical mirror analyzer with numerous gases available as primary ion source. Allows analysis of monolayer films. Can provide information on molecular orientation, contamination thickness, oxide layer thickness, etc. In ISS, a primary ion beam in the 0.5-5keV energy range is focussed onto a solid target specimen. Interactions between the primary ion beam and the target results in the production of scattered primary ions and neutrals, sputtered target material ions or neutrals and the production of secondary electrons and x-rays. | EDS/WDS - Energy and Wavelength Dispersive X-ray Spectroscopies Used in conjunction with either SEM or STEM to provide elemental information about the region visible in the associated micrographs. An effective method for analyzing for the main components as well as low level (nominally 0.1%) contaminants in relatively thick (several micron) layers. Analyzes volumes in the size range of 0.5-10µm in the SEM and as small as 10nm in the STEM. Elements sodium and heavier can be easily detected. |
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RGA - Residual Gas Analysis Allows mass fragments present in an evacuated chamber to be identified. The mass fragmentation pattern can frequently be used to identify the original chemical structure of a gas if the basic elemental composition is known and by making reasonable assumptions about possible chemical interactions. The typical quadrupole based mass spectrometers used in RGA can identify molecular fragments with unity resolution. | IR - Infrared Spectroscopy Studies the molecular vibration spectrum of a sample by passing infrared radiation through it and measuring the amount of absorption at each frequency. Fourier transform infrared spectroscopy (FTIR) is an application of the IR technique in which the collected data is mathematically transformed with a background spectrum collected with no sample in the excitation beam. The difference in the two methods is primarily in the speed, FTIR being faster by at least two orders of magnitude. |
| Other Services
Most methods for specimen preparation and analysis are available upon request. The techniques mentioned below are those most frequently utilized in conjunction with our standard services. Prices will be quoted on a per sample or per project bases: |
Special Services
Materials Research Laboratories, Inc. specializes in the total solution of materials problems. Detailed scientific services are available in the following general areas:
- Morphing through Videotape - Image Enhancement including Colorization - Data Generated onto Transparencies upon Request - In House State-of-the-Art Data / Image Scanners |