Pyrolysis study of solution-derived superconducting YBa2Cu3O7 films: disentangling the physico-chemical transformations

Bohores Villarejo, Cornelia Pop, Sussagna Ricart, Bernat Mundet, Anna Palau, Pere Roura-Grabulosa, Jordi Farjas, Teresa Puig * and  Xavier Obradors *. 
J. Mater. Chem. C, 2020,8, 10266-10282
DOI: 10.1039/D0TC01846E

Continue reading

Relevance of the Formation of Intermediate Non-Equilibrium Phases in YBa2Cu3O7–x Film Growth by Transient Liquid-Assisted Growth

Silvia Rasi, Laia Soler, Júlia Jareño, Juri Banchewski , Roger Guzman, Cristian Mocuta, Martin Kreuzer, Susagna Ricart, Pere Roura-Grabulosa, J Jordi Farjas, Xavier Obradors and Teresa Puig
Journal of Physical Chemistry C 124, 15574-15584, 2020
DOI: 110.1021/acs.jpcc.0c03859

Continue reading

Coated Conductor technology for the beamscreen chamber of future high energy circular colliders

Teresa Puig, Patrick Krkotic, Artur Romanov, Joan O’Callaghan, Danilo Andrea Zanin, Holger Neupert, Pedro Costa Pinto, Pierre Demolon, Ângelo Rafael Granadeiro Costa, Mauro Taborelli, Francis Perez, Montse Pont, Joffre Gutierrez and Sergio Calatroni. Superconductor Science and Technology

Continue reading

Band Gap Tuning of Solution-Processed Ferroelectric Perovskite BiFe1–xCoxO3 Thin Films

Pamela MachadoMateusz ScigajJaume GazquezEstel RuedaAntonio Sánchez-DíazIgnasi FinaMartí Gibert-RocaTeresa PuigXavier ObradorsMariano Campoy-Quiles, and Mariona Coll*Chem. Mater.201931 (3), pp 947–954  DOI: 10.1021/acs.chemmater.8b04380

Ferroelectric perovskite oxides are emerging as a promising photoactive layer for photovoltaic applications because of their very high stability and their alternative ferroelectricity-related mechanism for solar energy conversion that could lead to extraordinarily high efficiencies. One of the biggest challenges so far is to reduce their band gap toward the visible region while simultaneously retaining ferroelectricity. To address these two issues, herein an elemental composition engineering of BiFeO3 is performed by substituting Fe by Co cations, as a means to tune the characteristics of the transition metal–oxygen bond. We demonstrate by solution processing the formation of epitaxial, pure phase, and stable BiFe1–xCoxO3 thin films for x ≤ 0.3 and film thickness up to 100 nm. Importantly, the band gap can be tuned from 2.7 to 2.3 eV upon cobalt substitution while simultaneously enhancing ferroelectricity. As a proof of concept, nonoptimized vertical devices have been fabricated and, reassuringly, the electrical photoresponse in the visible region of the Co-substituted phase is improved with respect to the unsubstituted oxide.

Faceted‐Charge Patchy LnF3 Nanocrystals with a Selective Solvent Interaction

Martínez‐Esaín, J. , Puig, T. , Obradors, X. , Ros, J. , Yáñez, R. , Faraudo, J. and Ricart, S. (2018)  Angew. Chem. Int. Ed.

doi:10.1002/anie.201806273

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.

Electrochemical Tuning of Metal Insulator Transition and Nonvolatile Resistive Switching in Superconducting Films

Anna Palau*,Alejandro Fernandez-RodriguezJuan Carlos Gonzalez-RosilloXavier GranadosMariona CollBernat BozzoRafael Ortega-HernandezJordi SuñéNarcís MestresXavier Obradors, and Teresa Puig. ACS Appl. Mater. Interfaces, 2018, 10 (36), pp 30522–30531.

DOI: 10.1021/acsami.8b08042

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.

Institut de Ciència de Materials de Barcelona ICMAB CSIC

Address

Campus de la UAB, 08193 Bellaterra, Barcelona, Spain
+34 935 801 853 ext 371 
hr_suman@icmab.es