The transmission electron microscope (TEM) offers the possibility of analyzing high quality high contrast images. It complements other microscopic equipment in the Center like the optical and atomic force scanners stated Cedenna’s director Dora Altbir Drullinsky, while the researcher Juliano Casagrande Denardin added that it is an essential piece of equipment for all of the Center’s areas of research.
Using an electron beam that passes over the sample, the center’s new transmission electron microscope can show images magnified a million times. This level of magnification is important given that optical microscopes can only magnify up to a thousand times and a scanning electron microscope (SEM) only reveals information about the surface or topography of a sample. The new equipment for the Center for the Development of Nanoscience and Nanotechnology allows for observing the crystalline network of materials, in effect, the spatial organization of the atoms that constitute materials.
Cedenna’s director, Dr. Dora Altbir Drullinsky, stated that the device installed in the Rector Eduardo Morales Santos Building at the Universidad de Santiago de Chile cost close to 450 million pesos. The resources managed directly by Dr. Altbir were a contribution of the basal program to provide the Center with the highest technology in this area.
The director explained the new TEM is the ideal device for observing and studying materials at scales from 1 to 100 nanometers. It was incorporated into the Electron Microscope Laboratory, where it complements the functions of the scanning electron and atomic force microscopes.
The TEM was installed at Cedenna last week and Dr. Juliano Casagrande Denardin, who is in charge of the laboratory, personally supervised each stage. “It has been a dream of our researchers because this an essential piece of equipment for all the areas of research of the Center, such as the material, physical, nanotechnological and biological sciences”, stated Dr.Casagrande, who has extensive experience with this type of equipment.
The researcher Esteban Vargas Rojas explained that the new microscope will allow for characterizing nanostructured metallic, ceramic, polymeric and oxide materials, as well as biological structures like cells and bacteria and that at the nanometric scale it allows for observing nanoparticles, nanotubes, nanowires and ultra-thin films developed a Cedenna.
What makes this microscope distinct is its capacity to obtain well-defined high contrast digital images using low accelerating voltages for the electron beam, which minimizes the risk of structurally and morphologically altering sensitive and fragile samples.
The system emits an electron beam down a vertical tube guided by electromagnetic lenses. The beam passes through the sample located in the middle of the tube and is transmitted to a screen at the base of the device.
Because the electron wavelength is lower than that of visible light, it is possible to view very small structures. The projection is captured and transmitted to a computer where the information is selected, filtered and reconstructed to process an image or a pattern of spatially distributed characteristic points that represents the digital fingerprint of the material.