Scanning electron microscopy examines structure by bombarding the specimen with a scanning beam of electrons and then collecting slow moving secondary electrons that the specimen generates. These are collected, amplified, and displayed on a cathode ray tube (CRT, typically a slower version of the picture tube of a television set). The electron beam and the cathode ray tube scan synchronously so that an image of the surface of the specimen is formed. Specimen preparation includes drying the sample and making it conductive to electricity, if it is not already. Photographs are taken at a very slow rate of scan in order to capture greater resolution. All our SEMs use digital imaging. SEM is typically used to examine the external structure of objects that are as varied as biological specimens, rocks, metals, ceramics and almost anything that can be observed in a dissecting light microscope. The JEOL JSM-880 is used for smaller samples, as specimens have to fit inside the lens. Maximum sample size is 1 cm long x 3 mm wide x 2 mm thick. Specimens are mounted on "boats".
JEOL JSM-880 High Resolution SEM Characteristics
The JEOL JSM-880 consists of an SEM electronic console that is mated with a TEM column. Accordingly, the specimen carriers must be small enough to fit within the objective lens. Instead of stubs, "boats" are used that are made of bent copper strips that are about an inch long and a cm wide. The working distance is frequently -1 to -3 mm, which limits the space available for imaging.
Below are some examples of boats used for the JSM-880. Because of its high resolution, including material may be visualized on the surface of the specimen, increasing the difficulty of preparing artifact free coatings. The specimen carrier of the JSM-880 is interchangable with that of the JEOL-2000FX TEM, so the same specimen may easily be examined in both microscopes. Boats are a specialty item that is not made by routine EM supply houses and therefor are recycled in the SRNEML.
The maximum size of the area that can be imaged is 1 cm long by 3 mm wide and up to 2 mm thick.