Electron Microscopy (11th-12th)

TOPICS –

1. Materials Science: Students would learn how to properly prepare metal and oxide samples for the x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). This project involves cutting and mechanically polishing process to prepare desired sample surface to carry out a variety of experiments related to phase analysis using x-rays, backscattered electron imaging to study imaging contrast differences, performing specific point analysis using x-rays to identify individual particles. There will be at least two oxide ceramics, two metal alloys samples that will be help students to understand the differences not only in terms of materials properties but optimizing SEM imaging conditions for different types of samples. At the end of this project, the aim is to develop basic understanding about analyzing material surface properties; phase differences during optimized XPS and SEM imaging conditions. (Time: 3 days)   

2. Environmental and Life Sciences: For this project, students will have opportunity to study a variety of environmental and biological samples. Students will choose at least five insects or plant tissue samples. These samples will be prepared for XPS and electron microscopy experiments by either slicing them using microtome or preparing them using other sample preparation methods. Thin sections of environmental and biological samples will be sputtered with gold or carbon to apply top conducting layer for EM experiments. This layer will help to improve imaging quality for accurate imaging of sample surface morphology. During this project, the students will be introduced to XPS, time of flight secondary ion mass spectrometry (ToF-SIMS), high vacuum and variable pressure scanning electron microscopes including hands on experience about operation of high-end electron microscopes. (Time: 2 days)  

TECHNIQUES –

3. X-ray photoelectron spectroscopy (XPS): This project will use XPS instrumentation to identity material chemistry, binding energy and valence states. XPS is top surface science materials analysis techniques widely used by scientists and engineers in a variety of disciplines. This technique identify information from first few atomic layers making it a popular choice in advanced technology development. (Time: 3 days)

4. Focused Ion Beam (FIB): This project will use our Focused Ion Beam (FIB) to examine various materials and make controlled sections in them in an area less than width of the human hair. The students will see demonstrations about designing various patterns using engineering design software or imaging software. FIB will use these patterns to replicate its design on any material surface of our choice. This application is important for nanotechnology as FIB has capability to manipulate materials surfaces at the nanoscale. The students will also learn how beam energy conditions and type of material surface affect the pattern writing quality and conditions. (Time: 1 day)

5. Transmission Electron Microscopy (TEM): This project will cover basics of TEM and its operation. Differences between and SEM and TEM imaging techniques will be discussed with details about proper sample preparation techniques. Students will be introduced with 120 kV TEM with nanomaterials samples. Students will be taught about how to calculate size distribution of nanoparticles in different media. Image processing software like ImageJ may be utilized to calculate average particle size, volume and size distributions. (Time: 1 day)

Students should bring:

• Closed-toe shoes
• Long pants (no shorts are permitted in the labs)
• And should declare to staff if they have a pacemaker or iplanted metallic medical device