“Molecular Clusters” on the Surface of an Oxidizing Metal
FIELD ion microscopy, which holds the possibility of resolving the individual atoms in a metallic surface, should in principle be a powerful tool for the study of reactions on surfaces. As part of an extensive study of the mechanism of oxidation of several metals, we have recently observed the formation of characteristic, reproducible, small clusters of atoms of regular shape when a perfect iridium surface is exposed to oxygen.
Studies of dislocations by field ion microscopy and atom probe tomography
Alan Cottrell was among the first to recognize the potential of field ion microscopy for the atomic-scale study of crystal defects. The study of atomic configurations at the core of dislocations by this method proved to be unexpectedly difficult, because of the mechanical stresses imposed on the specimen by the high electric field. The development of atom probe tomography revitalized such studies. In particular, the atom probe technique permitted the first direct observations of solute atom distributions in the region of dislocations and confirmed the existence of so-called ‘Cottrell Atmospheres’ which are of great importance in the understanding of phenomena such as strain ageing. Atom probe studies of dislocation–solute interactions in a diverse range of alloy systems are outlined.
Kidney and urinary tract diseases in the newborn
Kidney and urinary tract diseases in the newborn / , Kidney and urinary tract diseases in the newborn / , کتابخانه دیجیتال جندی شاپور اهواز