AES is closely related to XPS. In Auger electron spectroscopy, electrons are ejected from a solid by an energetic electron beam. Once the core electron is ejected, conservation of energy mandates that an electron from a higher atomic orbital descends to fill the lower vacancy with the subsequent emission of a secondary Auger electron. The Auger electron is then focused by an electrostatic analyzer onto a solid state detector. The energy of the Auger electron is quantized by the atomic structure of the emitting atom. Only those electrons emitted from the first several atomic layers make it to the detector without losing energy through collisions with the lattice. Because of the exciting electron beam and the high level of electron noise in the analysis chamber, Auger spectra are typically recorded in derivative mode. Auger energies are not useful for determining the chemical states of surface atoms. Line intensities are proportional to atomic composition so semi-quantitative analysis is possible. AES is an ultra-high vacuum technique. Typically, only conducting samples are analyzed by Auger electron spectroscopy.
Contamination in the manufacturing process often leads to costly production losses. Identifying the contaminant can help pinpoint the source of the problem and minimize negative effects. Constellation has the tools to effectively analyze and identify many types of contamination.
Incoming material inspection and verification is an important part of quality control in the aerospace, automotive and defense industries. Materials used in manufacturing processes are routinely analyzed for adherence to quality specifications, including SAE-AMS and military specifications (MIL-Spec). With an extensive array of analytical instrumentation and experienced chemists and scientists, Constellation can perform incoming chemical and physical tests on a wide range of materials. The laboratory provides testing using US Pharmacopeia, Reagent Chemical, and ASTM methodologies, as well as procedures developed to meet the customer’s
Manufacturers often encounter unknown materials in their processes. Such materials include an unknown substance discovered in the manufacturing process, a suspect material from a new supplier, or a poorly-performing material. Constellation specializes in the identification of most types of materials, including metals, plastics, minerals and liquids. Most materials can be identified based on chemical composition and physical properties. The material identifications can range from extensive analyses to ensure high-quality materials to positive material identification (PMI) screening methods for rapid comparison of unknown materials to known samples.
Constellation can provide analysis of the first several atomic layers of a solid sample using x-ray photoelectron spectroscopy (XPS) and/or Auger electron spectroscopy (AES). These techniques provide semi-quantitative analysis of the composition of the solid surface. These techniques are the instrumental methods of choice for characterization of such things as surface contamination, chemical imperfections and corrosion. Coupling the techniques with inert ion sputtering provides a semi-quantitative composition of the solid sample as a function of depth.