Low Voltage FESEM of Geological Materials

Low voltage BSE imaging using FESEM

Backscattered electron (BSE) imaging is most commonly performed by applying accelerating voltages of 10kV and above to the specimen. For imaging of surface detail, the application of a lower accelerating voltage results in less beam penetration, spread and overall specimen damage. A field emission scanning electron microscope (FESEM) operated with high emission current (50μA) was used to increa...

Mitigating Thermal Beam Damage with Metallic Coats in Low Voltage FEG-EPMA of Geological Materials

Field emission gun electronprobe microanalysis (FEG-EPMA) provides the analyst with the opportunity to characterize very small volumes of material. Using a low voltage source the irradiated volume is submicron. It is well known that some geological phases e.g. volcanic glass, carbonates, phosphates, hydrous silicates suffer beam damage under high beam current condition [e.g.1,2] and several aut...

Low-Voltage Ionization of Air with Carbon-Based Materials

Polycrystalline diamond and carbon nanotubes exhibit excellent vacuum field emission properties, characterized by low turn-on voltage and high current density. Their atmospheric field emission and ionization capabilities are reported in this paper. Highly graphitic polycrystalline diamond (HGPD) film was grown in a plasma-enhanced chemical vapor deposition process, and its ability to ionize atm...

Oblique impact jetting of geological materials

Raman Spectroscopy for Geological Materials Analysis

Natural rocks composing the Earth are complex. They consist of an aggregate of one or more minerals. Each mineral can be defined by its chemical composition and its crystalline structure and sometimes can also contain fluid inclusions. Geologists need a powerful characterization technique to get detailed information on the rock formation history. Raman spectroscopy is extremely information-rich...