ELECTRON MICROSCOPY AND SCANNING PROBE MICROSCOPY: INTRODUCTION TO SEM, TEM AND AFM

The teaching is included among the complementary training activities for the Doctoral Course in Sustainable Chemistry. Students will address scientific topics in the field of chemistry for the development of industrial processes and the design of materials that contribute to the sustainable development of our society. To this purpose, nowadays it is pivotal the use of analytical techniques capable of revealing the properties of matter up to the nanometric scale and, possibly, further. Based on these considerations, electron transmission and scanning microscopies (TEM, STEM and SEM) and atomic force microscopy (AFM) have established themselves as essential experimental tools in the field of modern materials science. These techniques, each with its own peculiarities, allow us to visualize the topography of the samples with nanometric spatial resolution, combining simultaneous and highly localized measurements of chemical composition, electrical, magnetic and mechanical properties. The course is aimed at giving a broad overview of the development and use of these analytical techniques, progressively introducing the specific characteristics of the instruments and the specific interactions of matter with the selected probe (i.e., AFM tip or electrons). The final goal is to allow atomic and electron force microscopes to be exploited in the proper manner and to inspire their use for investigating new sustainable processes and materials.

The student will be able to:
- describe the basic physical principles used in AFM and electron microscopy (EM) imaging;
- provide correct interpretation of the data collected by AFM and EM;
- describe other microscopy techniques that have been developed on the basis of AFM and EM;
- consider the limitations of the techniques and select the most suitable method to address a specific research task;
- consider the potentiality of these techniques for the study and characterization of sustainable processes and materials of interest;
- integrate the knowledge acquired during this course into scientific discussions.

Basic knowledge of optics, physics of waves, electromagnetism, materials science and nanomaterials.

Part I (15h). Atomic force microscopy (AFM):
- Introduction to scanning probe microscopy.
- The harmonic oscillator and the characterization of the AFM cantilever motion.
- Force between the AFM probe and the sample surface.
- AFM instrumentation.
- AFM modes: static (contact) and dynamic AFM.
- AFM for analysis of topography.
- Work function, contact potential and Kelvin Probe AFM.
- Mapping of mechanical properties using force-distance curves.
- High-speed AFM for the study of biological samples.
- Combination of AFM and optical spectroscopies: near-field microscopies.

Part 2 (15h). Scanning and transmission electron microscopies:
- Introduction to microscopy: fundamentals of light microscopy.
- Geometrical optics.
- Visible light and electron features: a comparison.
- Diffraction and spatial resolution: limitations of light spectroscopy.
- Electron guns and electron lenses.
- The transmission electron microscope.
- The scanning electron microscope.
- Spectroscopies in the electron microscope: energy dispersive X-ray spectrometry (EDS or EDX), electron energy loss spectroscopy (EELS), electron backscatter diffraction (EBSD).

J. Goldstein et al., "Scanning Electron Microscopy and X-ray Microanalysis", Springer, Fourth Edition, 2018.
D.B. Williams and C.B. Carter, "Transmission Electron Microscopy, A text for materials scientists", Springer, 2009
B. Voigtländer, “Atomic force microscopy”, Springer, Second Edition, 2019.
A. Toshio, "High-speed atomic force in biology", Springer Edition, 2022

The assessment of learning takes place through a written report. The exam is aimed at verifying and evaluating the student's ability to understand and discuss an application of at least one experimental technique covered during the course. The student must prepare his/her report based on the results of two scientific articles of his/her choice. The articles must report the use of AFM and electron microscopies and they must be published in a peer-reviewed scientific journal. The student must propose the selected scientific article to the teacher, who will confirm its adequacy and compliance with the topics of the course. The student must demonstrate knowledge of the experimental technique, critical thinking and the ability to summarize the topic in a formal and concise way, using an appropriate scientific language.

Teaching is organized in lectures. PowerPoint slides will be used during the lessons. The material for teaching will be shared with the students.

Accessibility, Disability and Inclusion

Accommodation and support services for students with disabilities and students with specific learning impairments:
Ca’ Foscari abides by Italian Law (Law 17/1999; Law 170/2010) regarding supportservices and accommodation available to students with disabilities. This includes students with mobility, visual, hearing and other disabilities (Law 17/1999), and specific learning impairments (Law 170/2010). In the case of disability or impairment that requires accommodations (i.e., alternate testing, readers, note takers or interpreters) please contact the Disability and Accessibility Offices in Student Services: disabilita@unive.it.

oral