Crossover between Superconductivity and Magnetism in YBCO-SRO nanostructures
V Suresh Kumar1*, H. J. Liu2, J. C. Lin2, Y. C. Chen1, Y. H. Chu2
1Department of Physics, National Cheng Kung University, Tainan, Taiwan
2Department of Materials Science and Engineering, National Chao Tung University, Hsinchu, Taiwan
* presenting author:Vandrangi Suresh,
By a systematic variation of doping concentration of itinerant ferromagnetic SrRuO3 (SRO) in the matrix of superconducting YBa2Cu3O7 (YBCO), forming nanostructures that are structurally phase separate, we are able to demonstrate a low temperature crossover between superconductivity and magnetism. Starting from a much diluted concentration of SRO in YBCO-SRO nanostructures, which exhibits an insulating phase at high temperatures and superconducting phase at low temperatures, by increasing the magnetic interactions as a function of SRO doping, we investigated the electronic correlations and the interplay between superconductivity and magnetism throughout the temperature regime. A crossover from the superconducting phase to the magnetic phase with increasing density of nano-size SRO crystallites in the YBCO matrix is observed as a consequence of competing interactions between these two ordered phases.

Keywords: Superconductivity, Magnetism, Strongly correlated electrons, Nanostructures