Scanning Electron Microscope

Scanning Electron Microscope and X-Ray Detector

SCANNING ELECTRON MICROSCOPE

JEOL JSM-6390LV/LGS Scanning Electron Microscope

Magnification of the JEOL JSM-6390LV/LGS is on the order of 300,000x magnification, where fine details of specimens can be observed
The JSM-6390 is a high-performance, low cost, scanning electron microscope with a high resolution of 3.0nm
The customizable GUI interface allows the instrument to be intuitively operated, and Smile Shot^TM software ensures optimum operation settings
The JSM-6390 specimen chamber can accomodate up to 6-inches in diameter
Standard automated features include auto focus/auto stignator, auto gun (saturation, bias, and allignment), and automatic contrast and brightness
The JSM-6390 is used in many and varied applications

JEOL JSM-6390LV/LGS Specifications

Magnification	5 to 300,000x
kV	0.5 to 30kV
SEI @ 30kV	3nm
SEI @ 1kV	15nm
BEI @ 30kV	4nm
Stage X, Y, Z	80mm x 40mm x 48mm
EDS Geometry	35° TOA @ 10mm

What is a Scanning Electron Microscope?

The SEM is a type of electron microscope that creates various images by focusing a high energy beam of electrons onto the surface of a sample and detecting signals from the interaction of the incident electrons with the sample’s surface.

The primry function of the SEM is an IMAGING platform that can image using secondary electrons (SE) or backscattered electrons (BSE).

When coupled with X-ray detectors, we can determine COMPOSITIONS of materials.

Scanning Electron Microscope: Main Components

components Vacuum system

coherent electron beam

Electron Gun

Tungsten filament
Accelerating voltage

Lens system

Electromagnetic lenses

Scan Unit

Imaging

Detector Units

BSE
SE
X-Ray (EDS/WDS)

Scanning Electron Microscope: Signals

Electrons react with specimen to produce different signals:

Secondary Electrons (SE)
Backscattered Electrons (BSE)
Characteristic X-Rays (EDS/WDS)

How Does a SEM Work?

An electron gun generates an electron beam
The electron beam is focused through a set of electromagnetic lenses
Imaging occurs through the scan unit
Various detectors acquire the various signals to display an image

Magnification

Magnification is a function of the raster area.

MAGNIFICATION = Size of Raster on Viewing Screen/Size of Raster on Specimen

Sample Preparation

Various sample preparation methods and mounting methods are used for SEM imaging and analysis including adhesion of dry samples to metal stubs, epoxy-embedded grain mounts of particales, polished thin sections, biological samples, and even frozen samples requiring cooling stages.

Stub Mounts