Scanning Electron Microscope - Nanoscience and Nanotechnology - Engineering Physics 2

TL;DR

Learn how a scanning electron microscope analyzes samples at the nano level using electron beams and lenses.

Transcript

hello my dear students in this lecture we are going to learn scanning electron microscope now my dear students to understand this scanning electron microscope in previous lecture we have discussed about the tools in nanotechnology and in that tools i have discussed three microscopes right that is esem pem and afm so one by one we are learning these... Read More

Key Insights

• 😁 SEM uses electron beams and lenses to magnify nano-sized samples.
• 📤 Beam interactions produce secondary electrons, backscattered electrons, and x-rays for analysis.
• 😁 Magnetic lenses aid in focusing the electron beam for better resolution.
• 🔍 Analyzer processes and displays magnified images on a monitor for examination.
• 🤫 SEM functions by utilizing electron gun, anode, magnetic lenses, scanning coil, objective lens, and analyzer.
• ❓ Understanding the interactions of electrons with the sample is crucial for SEM analysis.
• 💦 Block diagrams can simplify the understanding of SEM working principles.

Questions & Answers

Q: How does a scanning electron microscope work?

A scanning electron microscope uses electron beams and lenses to magnify nano-sized samples and analyze them through secondary electrons, backscattered electrons, and x-rays.

Q: What are the three types of interactions observed when the electron beam strikes the sample?

The three types of interactions are the production of secondary electrons, backscattered electrons due to elastic scattering, and x-rays from inner cell electron knock-offs.

Q: What is the function of the magnetic lenses in a scanning electron microscope?

The magnetic lenses focus the electron beam to decrease its size up to 40 to 50 m astron, aiding in better resolution and magnification of the sample.

Q: How are the secondary electrons, backscattered electrons, and x-rays analyzed in a scanning electron microscope?

An analyzer processes and analyzes the intensity of secondary electrons, backscattered electrons, and x-rays, which are then displayed on a monitor for examination.

Summary & Key Takeaways

• Scanning Electron Microscope (SEM) magnifies nano-sized samples using electron beams.

• Beam interactions produce secondary electrons, backscattered electrons, and x-rays.

• The analyzer processes and displays the magnified image on a monitor for analysis.