Transmission Electron Microscopy

Abstract

Listen

Translate article

Conventional TEM (CTEM) is referring to the basic TEM techniques, i.e., electron diffraction and imaging techniques such as bright-field (BF), dark-field (DF) and high-resolution TEM (HRTEM). These techniques, in general, provide morphology and structural analysis of the specimen material. CTEM has been used to distinguish the analytical TEM tools that appeared much later in the history of TEM, including scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDX) techniques. Analytical TEM techniques are sensitive to the chemical and electronic structures of the specimen, sometimes are capable in providing crystal structures as well. However, TEM techniques have been developing quickly in recent years and often utilize the advantages of both CTEM and analytical TEM. For example, electron diffraction techniques are considered to be CTEM. However, a newly developed technique, scanning electron nanodiffraction (SEND), has combined features of the CTEM and STEM by Tao et al. (Phys Rev Lett 103:097202, 2009). Using SEND, the variation of certain type of electronic structures can be mapped in real-space by Zuo and Tao (Scanning transmission electron microscopy: imaging and analysis. Springer, London, 2010). Moreover, some techniques that were never used in TEM have emerged and show interesting potential in a number of research areas. One of them is the secondary electron microscopy (SEM) installed in STEM, benefited from the development of the SEM detectors (Zhu et al. Nat Mater 8:808, 2009). The capability of atomic resolution EELS and EDX has exhibited a promising future that the chemical or electronic structures may be obtained simultaneously with the crystal structure. All the above accomplishments are suggesting that the difference between CTEM and analytical TEM could be diminishing in the fast development of the TEM techniques.