quora
Nobody downloaded yet

Low Voltage Scanning Electron Microscopy - Research Paper Example

Comments (0) Cite this document
Summary
In the paper “Low Voltage Scanning Electron Microscopy” the author examines low voltage scanning electron microscopy, which denotes the use of scanning electron microscopy and uses few kilo electron-volts (<5 keV) for accelerating the electron beam used in scanning…
Download full paperFile format: .doc, available for editing
GRAB THE BEST PAPER96% of users find it useful
Low Voltage Scanning Electron Microscopy
Read TextPreview

Extract of sample
"Low Voltage Scanning Electron Microscopy"

Download file to see previous pages Working Principles of Scanning Electron Microscopy (SEM) Scanning electron microscopes (SEMs) are microscopes, which produce sample images by scanning the samples using a beam of focused electrons. The focused beam of electrons interacts with electrons within the sample to produce differing signal strengths that can be detected by a secondary electron detector. The focused electrons hit the sample surface, where they either get reflected as back-scattered electrons (BSE) due to inelastic scattering or cause an emission of electrons from the sample surface as secondary electrons (SE) due to elastic scattering (Lyman, 1990). The SE are emitted from the k-orbitals of the sample once the electrons in the beam hit them in a strong enough way that displaces them from the orbital. Both BSE and SE show different properties of the sample material, which commonly includes composition and topography (Boyes, 2000). The focused beam of electrons is scanned by raster scanning and position of the beam is combined with the signal from the BSE and SE to develop an image. This type of microscopic observation can attain resolutions that are better than a nanometer. The focused beam used in SEM is produced by thermionic means from an electron gun consisting of a cathode made of tungsten. Tungsten is preferable because of its relatively lower vapor pressure and high melting point. Additionally, it is cost-effective because it is relatively cheap. The produced beam passes through two lenses that focus it onto the specimen. The energy of the beam ranges from 0.2 keV to 40 keV depending on the design of the microscope. The focus offers a spot diameter of approximately 0.4 nanometers to 5 nanometers (Joy & Carolyn, 1996). On reaching the final lenses in the column the beam is deflected by a pair of deflecting plates, which deflect it in two planes (X, Y planes) so as to create a raster scan area that is rectangular over the sample’s surface (Asmar et al., 2004). The interaction of beam electrons and the sample make the electrons lose energy through repeated random scattering, which occurs near the surface or much deeper depending on the projection energy in keV. This interaction volume from which energy is released in form of electrons to create the image is known as the interaction volume. The interaction volume is determined by the landing energy of the electrons from the projected beam as well as density and atomic number of the material under observation as the sample. Technically, the differences between HVEM and LVEM are a result of differences in landing energy determined by the electron accelerating voltage. The acquired signals are detected and amplified to develop images. The differences of detected signals are represented by variations in brightness on the visual display. The resultant image is thus a representative of electron energy emitted from the sample’s surface through inelastic and elastic scattering. The Unique Nature of Low voltage scanning electron microscopy (LVSEM) According to Joy and Carolyn (1996), even prior to practical use of scanning electron microscopes, it had been recognized that scanning at low electron accelerating voltage (<5 keV) would improve the process. ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“Low Voltage Scanning Electron Microscopy Research Paper”, n.d.)
Low Voltage Scanning Electron Microscopy Research Paper. Retrieved from https://studentshare.org/biology/1461699-low-voltage-scanning-electron-microscopy
(Low Voltage Scanning Electron Microscopy Research Paper)
Low Voltage Scanning Electron Microscopy Research Paper. https://studentshare.org/biology/1461699-low-voltage-scanning-electron-microscopy.
“Low Voltage Scanning Electron Microscopy Research Paper”, n.d. https://studentshare.org/biology/1461699-low-voltage-scanning-electron-microscopy.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document
CHECK THESE SAMPLES - THEY ALSO FIT YOUR TOPIC
Magnetic Resonance Imaging
MRI is capable to generate clearer and more detained images as compared to the X-ray or Ultrasound scanning techniques. The physics behind the MRI scanning involves the complex nuclear physics and magnetic directivity and resonance. A MRI scanning device is fairly a large device, which is able to hold a person in it.
3 Pages(750 words)Research Paper
Use of the scanning electron microscopy in the food industry
Scanning electron microscopy (SEM), as well as other techniques such as energy dispersive spectroscopy (EDS) is an effective tool used for the identification and characterization of particulate contamination and foreign body contamination of food.
6 Pages(1500 words)Research Paper
Physics Research Paper
This project makes nanostructured crystalline TiO2 thin films as well as composite membranes of TiO2/Al2O3 that have the properties of photocatalytic, disinfection, separation, and anti-biofouling all at the same time. Acetic acid-based sol–gel route self-assembled surfactant molecules have been used in this process.
3 Pages(750 words)Research Paper
Methane Dry Reforming
Both carbon dioxide and methane are abundantly available and reforming them tends to produce synthesis gas with a low hydrogen to carbon monoxide ratio. This allows their preferential use for the production of liquid hydrocarbons using the Fischer-Tropsch synthesis process.
5 Pages(1250 words)Research Paper
The Impact of Fruit Juices on the Dental Erosion in Human Tooth Enamel
My thanks also go out to my teacher who was of immense help in helping me prepare the teeth samples and in take the Scanning Electron Microscope (SEM) samples for the experiment. Second Method Abstract In the second method, the project will also utilize Scanning Electron Microscope Images to help present a clear illustration of the harmful, erosive effects of drinking orange juice on the human teeth.
8 Pages(2000 words)Research Paper
Liquid Gated Biosensor
ibit optimal sensitivity 13 Highly Reduced Graphene Oxide, Graphene Oxide and Graphene 14 Atomic Structure in Reduced Graphene Oxide 15 Optimization of the CNTs Biosensor Response 16 Conductometric Biosensor mechanism 16 Infrared Spectroscopy mechanism 17 A quartz crystal microbalance (QCM) mechanism 17 Fig.
20 Pages(5000 words)Research Paper
College Physics
He concluded from his many experiments that a body is composed of two types of charged particles- positive and negative. Yes it is possible. Isotones are Nuclei of atoms with the same neutron number. Example: S-36, Cl-37, Ar-38, K-39, Ca-40. These nuclei contain 20 neutrons each, but with different number of protons: sulphur 16, chlorine 17, argon 18, potassium 19 and calcium 20 protons.
4 Pages(1000 words)Research Paper
Oes the molecular weight of polymers affect the performance of polymer (organic) solar cells
The large industry of polymers has introduced conducting polymers that can be used in the solar cells to improve the energy transformation. Physical and chemical properties of polymers may vary based on
1 Pages(250 words)Research Paper
Electrons in Atoms
The exact position of electrons on the orbits has never been calculated with precision. Scientists use estimations to refer to the location of a particular electron. An electron has a mass of 9.1095 x 10-31 and a charge of 1.6022 x 10-19 coulombs
5 Pages(1250 words)Research Paper
Cell biology
, properties, interactions with the environment, function, division, death and organelles (their locations within cells, functions, structures, compositions and adaptations) found within cells are delved into. The study of cells is done in a molecular level or is conducted suing
1 Pages(250 words)Research Paper
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Let us find you another Research Paper on topic Low Voltage Scanning Electron Microscopy for FREE!
logo footer
Contact us:
+16312120006
Contact Us Now
FREE Mobile Apps:
  • StudentShare App Store
  • StudentShare Google play
  • About StudentShare
  • Testimonials
  • FAQ
  • Blog
  • Free Essays
  • New Essays
  • Essays
  • Miscellaneous
  • The Newest Essay Topics
  • Index samples by all dates
Join us:
Contact Us