Science Behind the Service: Scanning Electron Microscopy

What is Scanning Electron Microscopy?      

Scanning Electron Microscopy (SEM) is an advanced microscope imaging technique that  uses a high energy electron beam to  create a greyscale image of a sample's surface topography and obtain composition data.  Variations in the level of grey shading creates a 3d like image depicting shapes, textures and  changes in the topography. Quality concerns can be evaluated for defects, corrosion and composition with the data obtained through the  Electron Microscope.

How does a Scanning Electron Microscope work?

     A scanning electron microscope uses a  focused beam of electrons to scan a sample creating two separate electron reactions,  backscattered electrons and secondary electrons. Backscattered electrons are high energy electrons  from the microscope's high energy electron gun that reflect off of a sample. These reflected electrons collected by the microscope give off information about the sample's surface creating a greyscale topographic image.  The beam of electrons also creates a second reaction called Secondary Electrons. Secondary electrons are created when the atoms of a sample absorb the radiation from high energy electrons, producing new electrons. These secondary electrons also contribute to the imaging and data.

These electrons originate from the atoms of the sampleThe microscope has receptors designed to collect these electron reactions to form the 3d like grey scale image. The first reaction occurs when the high energy electrons are d(r)eflected by the sample.  samples reflects electrons from the e some of the electrons from the beam. This The atoms in the a scanning electron microscope is designed to interact with a sample layer, penetrating a few microns below the surface. This high energy column of electrons will  produce 2 types of electron reactions, Backscattered electrons and Secondary electrons. Backscattered Electrons are high energy electrons that are reflected by the surface of a sample. These backscattered electrons originate from the electron gun that produces a high energy electron beam.  Secondary Electrons are produced when atoms on the surface of a sample are electrons that are produced Microscopes using visible light . Three dimensional, high resolution images can be obtained. Details as small as 70 angstroms can be depicted guests and employees. Hand sanitizer stations will be provided at each entrance. Guests are asked to provide their own masks. If a guest arrives with out a masks Micron will either provide one for them or ask that they return at another time with proper protection. All precautions are being enacted to combat the COVID-19 Virus crisis in accordance with CDC guidelines.  Common areas, work areas, conference rooms, restrooms, and packages will be sanitized regularly with disinfectant wipes and recommended all purpose cleaners.

Micron regularly hosts evidence inspections and can provide a myriad of tests including optical, metallurgical and scanning electron microscopy during a lab visit with all parties present. Large groups can be accommodated for the examinations. Climate-controlled
evidence storage is also available.

A retainer fee is required prior to examination to secure an inspection date. To schedule or obtain more information:
Email micronanalytical@compuserve.com or call us at (302) 998-1184
Ask for Heiki Heitur, our Senior Technologist.

Samples which need specific analyses not offered by Micron Inc. can be accompanied by a Chain of Custody Form and sent to fellow laboratories for further analysis.