Oxygen kinetics and charge doping for high critical current YBCO films
Members of our group, the Superconducting Materials and Large Scale Nanostructures (SUMAN) Group, were last week during four days at CosmoCaixa for the “Fira Recerca en Directe“, where research groups from different universities and research centers present their research to primary and secondary schools and families. Our group showed how to prepare superconducting thin films, and how levitating trains work.
This year, the 17th edition of the “Fira Recerca en Directe”, organized by the Parc Científic de Barcelona (PCB) in collaboration with Obra Social “la Caixa”, will count with the participation of some researchers from SUMAN group , which will show, among others, the levitating superconducting train.
Our PhD student Laia Soler Bru will defend her PhD thesis on Friday, 1 March 2019, at 11 am at ICMAB-CSIC. Liquid-assisted ultrafast growth of superconducting films derived from chemical solutions
A fast and single‐step preparation of patchy LnF3 faceted‐charge nanocrystals are described. These hexagonal faceted nanocrystals allow the spontaneous selective adsorption of cations or anions in the different faces, producing stable and well‐defined patches of different charge. The mechanism for the formation of the patches and the properties of the obtained nanocrystals were characterized by a combination of experimental techniques and all‐atomic molecular dynamics simulations. The spontaneous dual‐charged surface as well as the luminescence effects that can be achieved by doping host–LaF3 systems make these new nanocrystals interesting both from a fundamental point of view and for a wide range of applications.
Modulation of carrier concentration in strongly correlated oxides offers the unique opportunity to induce different phases in the same material, which dramatically change their physical properties, providing novel concepts in oxide electronic devices with engineered functionalities. This work reports on the electric manipulation of the superconducting to insulator phase transition in YBa2Cu3O7−δ thin films by electrochemical oxygen doping. Both normal state resistance and the superconducting critical temperature can be reversibly manipulated in confined active volumes of the film by gate-tunable oxygen diffusion. Vertical and lateral oxygen mobility may be finely modulated, at the micro- and nano-scale, by tuning the applied bias voltage and operating temperature thus providing the basis for the design of homogeneous and flexible transistor-like devices with loss-less superconducting drain–source channels. We analyze the experimental results in light of a theoretical model, which incorporates thermally activated and electrically driven volume oxygen diffusion.
