Microstructural phenomena and phase transitions of the Nd‐doped La1.85 Sr0 15 CuO4 system are studied in an electron microscope. In ion‐milled samples, twin domains appear and disappear as expected at the high temperature phase transition. At temperatures below the high temperature transition, these twin domains show a very subtle behaviour. Ground material even in the orthorhombic phase shows no twins at all. In ion‐thinned material a typical reduction of the domain size occurs after an electron illumination time of about one hour. Generally no reversible change of the twin configuration could be observed at the low temperature phase transition.
A new method which allows the detection of the superconducting phase transition of high-T, superconductors (HTSC) on a microscopic scale is reported. Micro-size holes in thin foils of superconducting material are examined in a transmission electron microscope at varying temperatures. The superconducting transition induces small changes in the image intensity within the holes, which can be detected by using electronic image analysis. Superconducting transition curves are then obtained for various types of high-T, superconductors and for given values of the applied magnetic field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.