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Atomic Force Microscopy Study Of Human Tooth Enamel Surfaces, Ph. Schaad, E. Paris, F. J. G. Cuisinier, J. -C. Voegel
Atomic Force Microscopy Study Of Human Tooth Enamel Surfaces, Ph. Schaad, E. Paris, F. J. G. Cuisinier, J. -C. Voegel
Scanning Microscopy
Human enamel features from individual crystals up to prisms were observed by atomic force microscopy (AFM). Low magnification images of vestibular tooth surfaces show the existence of enamel prisms appearing as deep holes. Individual, parallel enamel crystals show lateral faces elongated and formed by the (100) planes of hydroxyapatite (HA). Height differences between (001) faces create the roughness of enamel surface. Individual (001) crystal faces can be observed clearly at higher magnification and show the characteristic hexagonal shape with 60° angles between (100) faces. This study confirms the applicability of AFM for studying biological hydroxyapatite crystals.
Scanning Tunneling Microscopy: A Chemical Perspective, C. Julian Chen
Scanning Tunneling Microscopy: A Chemical Perspective, C. Julian Chen
Scanning Microscopy
In this review article, scanning tunneling microscopy (STM) is presented in a chemical perspective. The typical distance from the nucleus of the apex atom of the tip to the top-layer nuclei of the sample is 4-6 Å, where a strong attractive atomic force, i.e., a partial covalent bond, arises between the tip and the sample. The origin of the covalent bond is the back-and-forth transfer of electrons between two atoms, which Pauling has called resonance. While a bias voltage is applied between them, a net electron current in a specific direction arises. This tunneling current is a result of …
Morphology Studies Of Iron-Manganese Thin Films, G. Mathew, K. -W. Ng, A. R. Sethuraman, J. M. Stencel
Morphology Studies Of Iron-Manganese Thin Films, G. Mathew, K. -W. Ng, A. R. Sethuraman, J. M. Stencel
Scanning Microscopy
Fe-based catalysts are known to be effective for Fischer-Tropsch synthesis from coal but are sensitive to sulfur poisoning. Addition of manganese to these catalysts has been proposed in an effort to combat this catalyst deactivation. To investigate the fundamental physical aspects of Mn incorporation into Fe, different compositions of model thin films of Fe-Mn, ranging from 100% Fe to 100% Mn were studied for the very first time, using scanning tunneling microscopy (STM), atomic force microscopy (AFM) and scanning electron microscopy. Our preliminary results indicate that the grain size of iron varied from 50 nm to 150 nm using the …