StatusThe thesis was presented on the 6 February, 2012
Approved by NCAA on the 5 April, 2012
Abstract– 0.76 Mb / in romanian
– 0.88 Mb / in romanian
Dissertation contents:introduction, four chapters, general conclusions and recommendations, bibliography – 116 references. The work contains 129 pages of the main part, 4 tables and 58 figures.
Number of publications:the obtained results are presented in 43 scientific papers and one patent
Field of research: superconductivity in hybrid structures, spintronics.
The aim of the work: Establishment of conditions for reproducible manifestation of oscillations of the critical temperature and the re-entrance effect of superconductivity in layered structures superconductor-ferromagnet as a function of the thickness of the ferromagnetic layer; examination of the superconducting properties of single films of Niobium, and bi-layer structures of Niobium/Copper-Nickel; elaboration of practical recommendations for application of the obtained results for the development of superconducting spintronic devices.
The scientific originality of the research consists in: An original vacuum technology is developed for preparation of high quality nanostructures “superconductor/ferromagnet”, which allows to produce a series of superconducting structures with variable thickness of the films and strictly identical and controllable parameters in a single cycle of deposition; a double re-entrance of the superconductivity was primary observed on the bi-layered structures with constant thickness of superconducting Niobium layer and variable thickness of Copper-Nickel ferromagnetic alloy layer.
In frame of this work the main scientific and technical problem was resolved: for the first time a multiperiod reentrance superconducting behavior of multi structures based on Niobium and Cupper-Nickel alloy was observed and studied. The structures was produced using a special developed vacuum technology of magnetron sputtering, which can be exploited for reproducing of the necessary structures.
The practical importance of the research consists in: An original vacuum technology is developed for preparation of high quality nanostructures “superconductor/ferromagnet”, which can be used for producing of superconducting devices; passivation technological process is elaborated for a long-term stability of parameters of the fabricated nano-elements for superconducting spintronics.