Sample Preparation Equipment Documents

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Documentation in support of your JEOL product.

SEM and TEM Analysis of Cryomilled Nanocrystalline Al Powder

Cryomilling involves the ball milling of metal powders in a liquid nitrogen medium. It has been used to produce bulk nanocrystalline materials with high thermal stability [1]. The benefits of milling at cryogenic temperatures include accelerated grain refinement, reduced oxygen contamination from the atmosphere, and minimized heat generated during milling. This mechanical attrition process induces severe repetitive deformation in powders. During milling, the powder particles are repeatedly sheared, fractured and cold-welded, and severe plastic deformation effects the formation of nanostructures [2]. Cryomilled powders exhibit typical grain sizes of 20–60 nm [3].

SEM Backscattered-Electron Images of Paint Cross Sections as Information Source for the Presence of the Lead White Pigment and Lead-Related Degradation and Migration Phenomena in Oil Paintings

Scanning electron microscopy backscattered-electron images of paint cross sections show the compositional contrast within the paint system. They not only give valuable information about the pigment composition and layer structure but also about the aging processes in the paint. This article focuses on the reading of backscatter images of lead white-containing samples from traditional oil paintings (17th–19th centuries). In contrast to modern lead white, traditional stack process lead white is characterized by a wide particle size distribution. Changes in particle morphology and distribution are indications of chemical/physical reactivity in the paint. Lead white can be affected by free fatty acids to form lead soaps. The dissolution of lead white can be recognized in the backscatter image by gray ~less scattering! peripheries around particles and gray amorphous areas as opposed to the well-defined, highly scattering intact lead white particles. The small particles react away first, while the larger particles/lumps can still be visible. Formed lead soaps appear to migrate or diffuse through the semipermeable paint system. Lead-rich bands around particles, at layer interfaces and in the paint medium, are indications of transport. The presence of lead-containing crystals at the paint surface or inside aggregates furthermore point to the migration and mineralization of lead soaps.

SEM Technology Advances Energy Research

High-resolution field-emission scanning electron microscopes (FEG-SEMs) have proven to be very powerful tools for energy-related research. Developments in such areas as solar thin films, oil shale, catalysis, and fuel cells require sub-nanometer resolution SEMs with a versatile set of detectors. They also require advanced sample preparation and handling techniques, such as argon ion polishing and FIB (focused ion beam). This article discusses incorporation of both advanced sample preparation and handling techniques, and the newest SEM detectors and imaging capabilities to advance energy research.

Other Resources

The following resources are available concerning Sample Preparation related instruments:

  • Image Gallery
    -View a selection of Cross Section Polisher images
  • Mixed Media
    -View our series of videos on the use of the Cross Section Polisher