After briefly noting some development records in phase diagrams, the stoichiometry is dealt with in more details showing the
structural layer ordering in the superconducting cuprates and mentioning some correlation between thermodynamics and BSC theory
An intellectual account of of the physics of superconductivity was compared with citation and co-citation data during two historical periods that coincided with the introduction of its central explanatory theory (BCS). Factor analysis is used to investigate the co-citation data. The results give preliminary support to a hypothesis that distinguishes impact phases in the effect of the theory on the cognitive organization of the specialty. It is also observed that citation and co-citation data are separate types of information which, under some historical conditions, give differing results.
This paper deals with a physical-statistical analysis on the information flows in the field of superconductive thin films for 1949 to 1977. The classification of scientific research is done and an attempt is made to determine the correlations between the different types. The dynamics of growth of the number of publications is considered, and changes of researchers' scientific interests concerning the application of various chemical materials and structures in superconductive thin films are studied. The problems of professional mobility are also investigated. Conclusions are drawn on the development of the described field.
Anomalous temperature dependent changes were found in 2-1-2-2 Type Tl-containing high temperature superconductor around the TC1. The anomaly can be interpreted as relaxation changes due to Cooper pairing with energy predicted by the BCS theory.
Authors:G. A. Costa, A. Ubaldini, C. Artini, M. M. Carnasciali, and R. Masini
Summary A thermal study was performed on the RuSr2GdCu2O8 (Ru-1212) magnetic superconductor phase to investigate the effect of the annealing treatments in flowing O2 on the stability limit of the phase and on its structural, magnetic and transport properties. DTA-TG measurements were utilized to determine the decomposition process and the dependence of the decomposition temperature on the annealing atmosphere. The decomposition of the Ru-1212 phase was found sensitive to the oxygen partial pressure and increases with PO2 and the annealing time. The annealing treatments exert a depressing effect on the strength of the magnetic interaction, an enhancement on the superconductive properties and the vanishing of the magnetostriction. A decomposition reaction of Ru-1212 phase was proposed and discussed.
A numerical study of the thermodynamic properties of a superconducting quantum cylinder in a longitudinal magnetic field is carried out. Closed-form expressions for the critical temperature, the free energy, the heat capacity jump, and the magnetization difference between the superconducting and normal phases as functions of the nanotube parameters are obtained in limit cases.
The thread that runs through all research in the field of superconductivity is new physics through discovery of new materials. The knowledge of superconducting materials has become voluminous and complex. The comprehensive review of the superconducting materials is of particular importance. The main purpose of this report is to present the results of classification for chalcogenide superconductors. Superconducting critical temperature Tc, crystal-structure type and the references proper to these compounds are summarized. Brief survey of the superconductivity in chalcogen elements is also given. Furthermore, as representative sulfide and selenide, superconducting characteristics of CuRh2S4 and CuRh2Se4 will be shown.
Data obtained through letter poll over 143 researchers who authored the 240 highly cited documents (See the first phase of the study) were used to describe the informal aspects of communication between Chinese and non-Chinese superconductivity researchers. While non-Chinese researchers played both roles equally, Chinese scientists were the destination more often than they were the source in informal communication. Chinese scientists were less visible than their counterparts in the informal domain. The mapping of the informal communication activities among the superconductivity researchers shows that all Chinese scientists except Zhao ZX, a special liaison between the two groups of researchers, clustered away from their non-Chinese colleagues.
Authors:A. Tomasi, P. Scardi, F. C. Matacotta, and P. Nozar
Carbocuprate compounds are generally described as multiple perovskites with CO32- and Cu-O alternating layers containing Ba and/or Sr; they have gained an unexpected importance in the high temperature superconductivity field, because many compounds with transition temperature above 100 K belong to this class of materials.