Transmission Electron Microscopy (TEM) is a powerful imaging and analytical technique for investigating the morphology, structure, and chemical composition of a multitude of samples. For example, it is a primary tool for exploring the structure-property relationships of novel nanomaterials. A better understanding of the mechanisms that influence a material’s property on the atomic level is essential for developing new functional nano-devices for electronics, energy, and biological applications.1
In the TEM column, a beam of electrons - charged particles that can be accelerated and precisely focused by electromagnetic fields - is directed through an ultra-thin sample to produce high-resolution images. When the stream of electrons is transmitted through the sample, the scattered beams are collected in various ways by multiple detectors and cameras to form a variety of images, providing unique specimen information. Many critical processes take place in the electron column to achieve the desired imaging and data.
The TEM is a versatile, powerful characterization technique for the most advanced applications, especially for atomic resolution details. Compared to other imaging techniques, TEM offers unique advantages that make it a crucial tool in scientific research, particularly in materials science, the life sciences, and nanotechnology.
TEM is an important microscopy tool for chemical and structural characterization of materials at the nanoscale. It provides important details about complex microstructures, such as grain boundary or interface chemistries and orientations. The most powerful TEMs can produce atomic resolution images at the picometer scale, with both chemical and electronic information.
TEM is furthermore used to study the properties and structures of nanomaterials, such as quantum dots and nanowires. It allows researchers to analyze the characteristics of these materials at the atomic level, aiding in the development of innovative nanotechnological applications.
In the field of Life Sciences, TEM is used to study the ultrastructure of biological samples. JEOL’s lower energy TEMs (JEM-1400Flash and JEM-2100Plus) are routinely used for pathology and biological studies. By visualizing cellular components and their associations, TEM has shed light on the dynamics between cells, bacteria, parasites, and viruses.
Higher energy TEMs (JEM-F200 and the CRYOARM series) perform unparalleled work in research for life sciences and drug discovery. Cryo-EM has seen an enormous surge in growth in recent years. Dramatic improvements in resolution in Cryo-EM have resulted in an essential method for structural analysis of proteins and macromolecular assemblies. JEOL’s highly automated Cryo-EM workflows are capable of unattended acquisition of thousands of images of vitrified specimens. Using tomography, the TEM recreates a 3D structure of a virus or protein. JEOL’s CRYO ARMs achieve best-in-class resolution for single particle analysis (SPA) and excel in observation of electron beam-sensitive specimens.
Highly Adaptable and Powerful TEM Techniques
The TEM can be adapted to many specific types of research and beyond conventional imaging it can be used in multiple operating modes including:
- Scanning Transmission Electron Microscopy (STEM)
- Diffraction (MicroED)
- In Situ TEM for real time experiments in the operational state of samples
Additional options and features make the TEM more specifically tailored to the type of imaging and analysis to be performed.
- Aberration correction of higher order aberrations up to 5th order for high resolution TEM and STEM imaging
- Field-free Lorentz imaging of magnetic samples
- Cold Field Emission Gun allows more current in a smaller probe, improved spatial resolution, fine structure determination
- Large Area Silicon Drift Detectors for single atom sensitivity in EDS
- Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-ray Spectroscopy (EDS) for high spatial resolution atomic-scale microanalysis down to 30kV
- Advanced detectors
- EDM Electrostatic dose modulation
- Synchrony Nanosecond timing control
History of TEM
The first TEM was developed in the early 1930s and its development is credited to Max Knoll and Ernst Ruska. Ruska was awarded the Nobel Prize in Physics in 1986 for the development of TEM technology. JEOL developed and introduced its first commercial TEM in the 1940s and has been developing and producing TEMs designed for life sciences and material sciences ever since. Many of the world’s laboratories utilize JEOL TEM/STEMs to further their research efforts. With advancements such as in situ TEM techniques and Cryo-EM, TEM continues to evolve and expand its applications in various scientific disciplines.
1Atomic-Resolution Characterization Using the Aberration-Corrected JEOL JEM-ARM-200CF at the University of Illinois-Chicago