Introduction to Transmission Electron Microscopy: History and Principles

This lecture provides an introduction to transmission electron microscopy (TEM), covering its historical development and fundamental principles. The instructor begins by outlining the course structure and objectives, emphasizing the importance of understanding the physical contrasts relevant to the lecture. A brief history of TEM is presented, highlighting key milestones such as the invention of the first prototype in 1931 and the subsequent advancements leading to commercial instruments. The discussion includes the evolution of electron optics, the significance of aberration correction, and the impact of technological improvements on resolution. The instructor explains the basic components of a TEM, including the electron source, lenses, and the interaction of electrons with the specimen. Different types of contrast mechanisms, such as mass thickness contrast and diffraction contrast, are introduced, along with their applications in imaging crystalline specimens. The lecture concludes with an overview of electron-energy loss spectroscopy, detailing how it provides insights into the electronic structure of materials. Overall, this lecture sets the foundation for understanding the principles and applications of TEM in materials science.