Low Voltage Scanning Electron Microscopy

Write 7 pages with APA style on Low Voltage Scanning Electron Microscopy. 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 (&lt.5 keV) would improve the process.

Calculate the price
Make an order in advance and get the best price
Pages (550 words)
$0.00
*Price with a welcome 15% discount applied.
Pro tip: If you want to save more money and pay the lowest price, you need to set a more extended deadline.
We know how difficult it is to be a student these days. That's why our prices are one of the most affordable on the market, and there are no hidden fees.

Instead, we offer bonuses, discounts, and free services to make your experience outstanding.
How it works
Receive a 100% original paper that will pass Turnitin from a top essay writing service
step 1
Upload your instructions
Fill out the order form and provide paper details. You can even attach screenshots or add additional instructions later. If something is not clear or missing, the writer will contact you for clarification.
Pro service tips
How to get the most out of your experience with TermPapersForMe
One writer throughout the entire course
If you like the writer, you can hire them again. Just copy & paste their ID on the order form ("Preferred Writer's ID" field). This way, your vocabulary will be uniform, and the writer will be aware of your needs.
The same paper from different writers
You can order essay or any other work from two different writers to choose the best one or give another version to a friend. This can be done through the add-on "Same paper from another writer."
Copy of sources used by the writer
Our college essay writers work with ScienceDirect and other databases. They can send you articles or materials used in PDF or through screenshots. Just tick the "Copy of sources" field on the order form.
Testimonials
See why 10k+ students have chosen us as their sole writing assistance provider
Check out the latest reviews and opinions submitted by real customers worldwide and make an informed decision.
Communications
Thank you! It was great :)
Customer 452483, July 26th, 2021
Sociology
Thank you so much! Appreciate it!
Customer 452483, November 8th, 2021
Nursing
Good job!! Thank you!!!
Customer 452487, September 9th, 2021
Healthcare Writing & Communications
Excellent!! You’re awesome, thank you very much for all of your hard work & help!!
Customer 452483, October 24th, 2021
Psychology
Thank you so much for all of your hard work & help! It’s perfect! Appreciate it!!
Customer 452483, September 11th, 2021
Communications
Well done! I thank you very much!
Customer 452483, July 9th, 2021
Sociology
Perfect! Appreciate all of your help! Thank you so much!
Customer 452483, November 14th, 2021
Mathematics
Thank you so much!
Customer 452483, July 26th, 2021
Mathematics
Job WELL DONE! Thank You very much!!
Customer 452483, July 12th, 2021
Mathematics
PERFECT! Thanks a million, you're all awesome!!!!
Customer 452483, July 7th, 2021
English 101
Great work! Thanks!
Customer 452567, August 2nd, 2022
Other
I appreciate the help.
Customer 452567, March 18th, 2022
1159
Customer reviews in total
96%
Current satisfaction rate
2 pages
Average paper length
47%
Customers referred by a friend
OUR GIFT TO YOU
15% OFF your first order
Use a coupon TERM15 and enjoy expert help with any task at the most affordable price.
Claim my 15% OFF Order in Chat