Author: Mar Tristany

Hybrid YBa2Cu3O7 Superconducting–Ferromagnetic Nanocomposite Thin Films Prepared from Colloidal Chemical Solutions

Hybrid YBa2Cu3O7 Superconducting–Ferromagnetic Nanocomposite Thin Films Prepared from Colloidal Chemical Solutions

Elena Bartolomé, Pablo Cayado, Eduardo Solano,Cristian Mocuta, Susagna Ricart, Bernat Mundet, Marionna Coll, Jaume Gázquez, Alexander Meledin, Gustaaf van Tendeloo, Manuel Valvidares, Javier Herrero-Martín, Pierluigi Gargiani, Eric Pellegrin, Cesar Magén, Teresa Puig, Xavier Obradors. Adv. Electron. Mater. 2017, 1700037. DOI: 10.1002/aelm.201700037

High Tc superconductor–ferromagnetic heterostructures constitute an appealing playground to study the interplay between flux vortices and magnetic moments. Here, the capability of a solution-derived route to grow hybrid YBa2Cu3O7-ferromagnetic nanocomposite epitaxial thin films from preformed spinel ferrite (MFe2O4, M = Mn, Co) nanoparticles (NPs) is explored. The characterization, performed using a combination of structural and magnetic techniques, reveals the complexity of the resulting nanocomposites. Results show that during the YBCO growth process, most of the NPs evolve to ferromagnetic double-perovskite (DP) phases (YBaCu2−xyFexCoyO5/YBaCoFeO5), while a residual fraction of preformed ferrite NPs may remain in the YBCO matrix. Magnetometry cycles reflect the presence of ferromagnetic structures associated to the DPs embedded in the superconducting films. In addition, a superparamagnetic signal that may be associated with a diluted system of ferromagnetic clusters around complex defects has been detected, as previously observed in standard YBCO films and nanocomposites. The hybrid nanocomposites described in this work will allow studying several fundamental issues like the nucleation of superconductivity and the mechanisms of magnetic vortex pinning in superconducting/ferromagnetic heterostructures.

12-16 June 2017: Ferran at MagLab

The PhD student Ferran Vallés Pérez visited the National High Magnetic Field Laboratory in Tallahassee (Florida, USA) to perform electrical transport measurements on the superconducting films grown at ICMAB up to 35T, one of the highest DC fields on the earth, generated using a maximum electrical power of 23.3 MW. The study of these superconducting films is indeed performed with the challenging idea to use them for the fabrication of electromagnets that will be capable to generate these high magnetic fields with much less power consumption.

Jordi Martínez awarded at the “Jornades Doctorals 2017” UAB

Our PhD student, Jordi Martínez, has been awarded with the second prize for his poster, abstract and oral presentation entitled “Uncovering the surface chemistry of LnF3 nanoparticles” during the Jornades Doctorals 2017 organized by the Chemistry Department of the Universitat Autònoma de Barcelona (UAB).

Jordi Martínez is a predoctoral researcher doing his PhD thesis under the supervision of Susagna Ricart, from ICMAB, and Ramón Yañez, from the Chemistry Department of the UAB.

His research is devoted to the synthesis and characterization of LnF3 (lanthanide fluoride) nanoparticles. These nanoparticles are then used to nanostructure superconducting materials and providing them with different and interesting properties. 

Congratulations, Jordi! 

Untangling surface oxygen exchange effects in YBa2Cu3O6+x thin films by electrical conductivity relaxation

P. CayadoC. F. Sánchez-Valdés,  A. Stangl,  M. Coll,  P. Roura,  A. Palau,  T. Puig  and  X. Obradors*. Phys. Chem. Chem. Phys., 2017,19, 14129-14140. DOI: 0.1039/C7CP01855J0.1039/C7CP01855J
The kinetics of oxygen incorporation (in-diffusion process) and excorporation (out-diffusion process), in YBa2Cu3O6+x (YBCO) epitaxial thin films prepared using the chemical solution deposition (CSD) methodology by the trifluoroacetate route, was investigated by electrical conductivity relaxation measurements. We show that the oxygenation kinetics of YBCO films is limited by the surface exchange process of oxygen molecules prior to bulk diffusion into the films. The analysis of the temperature and oxygen partial pressure influence on the oxygenation kinetics has drawn a consistent picture of the oxygen surface exchange process enabling us to define the most likely rate determining step. We have also established a strategy to accelerate the oxygenation kinetics at low temperatures based on the catalytic influence of Ag coatings thus allowing us to decrease the oxygenation temperature in the YBCO thin films.

Xavier Obradors: “Research is a future investment, not an expense”

Last night, on May 24, Xavier Obradors received the Ambassador Award from the Regió 7 daily journal. Neus Munté, Minister of Presidency and government spokesperson, delivered the award. 

The awards ceremony took place in the Auditorium Plana de l’Om in Manresa, and Xavier was the first one to receive the award. During his speech, he said he was proud that this award linked his professional scientific life with his territory and his people. 

Xavier stated that scientists are facing global challenges, and that they keep progressing from the uncertainty and the unknown. In this way, he would like that the scientific advances achieved in the Research Centers could be transferred faster to the society, to the industry, to the people.

As ICMAB director, this is what he has been aiming for. “Research should become a benefit for our country; it is a future investment, not an expense. Our economy has no future without being strong in this area.”

Congratulations, Xavier, for this “Ambassador” award!

More information in Regió 7

Congratulations Juan Carlos !

The PhD Student Juan Carlos Gonzalez-Rosillo has defended his PhD thesis:

 

Title: Volume resistive switching in metallic perovskite oxides driven by the metal-insulator transition

 


Date:  Friday 19th May
Time: 11:30 am
Place: Auditorium of the Centre de Recerca Matematica (CRM) at the Facultat de Ciències-UAB


Abstract: Resistive-Random Access Memories (RRAM) are one of the most promising candidates to overcome the limitations of actual data storage technologies, due to their excellent performance. They are based on the Resistive Switching effect (RS), where the application of an electric field produces a reversible, non-volatile change in the resistance between two or more resistive states. In transition metal oxides, the motion of oxygen is widely accepted to play a key role in their outstanding properties. However, the exact mechanism governing this effect is material-dependent and for some of them it is still far to be understood. In this thesis, we present a novel Resistive Switching mechanism based on the Metal-Insulator Transition (MIT) in metallic perovskite oxides with strong electron-electron interaction. We analyse the RS behaviour of three different families of metallic perovskites: La1-xSrxMnO3, YBa2Cu3O7-x and RENiO3 and demonstrate that the MIT of these mixed electronic-ionic conductors can be tuned upon the application of an electric field, being able to transform the entire bulk volume.

 

Supervisors:
              Prof. Teresa Puig (SUMAN group, ICMAB)
              Dr. Anna Palau (SUMAN group, ICMAB)

PhD committee:
             President: Prof. Jordi Suñé (UAB)
             Secretary: Javier E. Villegas (CNRS-Thales)
             Vocal: Prof. Regina Dittmann (Forschungszentrum Jülich)

Xavier Obradors honored with the Ambassador Regió 7 Award

Xavier Obradors has been honored with the Ambassador Regió 7 Award, granted by the daily newspaper Regió 7.

The Regió 7 Awards, this year in their eighteenth edition, recognize people and organizations who have excelled in different fields related to economics and society.

Xavier Obradors has been awarded the Ambassador Award, which honors a person who has excelled in his work outside Central Catalonia while broadcasting the territory.

Xavier was born in Manresa, and since 2008 he is the ICMAB director. He studied physics at the Universitat de Barcelona, and earned his PhD from the same university in 1982,  having performed PhD research stays in Toulouse and Grenoble. After a period of postdoctoral fellow and Associate Professor (Prof. Titular) at the University of Barcelona, he became Research Scientist at CSIC in 1989, and Research Professor in 1992. His research interests cover a broad spectrum, from innovative materials preparation with controlled nano and microstructure, to the search for the comprehension of the physical mechanisms underlaying the magnetic and superconducting properties of materials. Currently, his research focuses in the nanoscale control of superconducting materials, with a special interest in low cost processing approaches. He is member of the “Superconducting materials and large scale nanostructures” SUMAN group at ICMAB.

15th-16th May: 6M FASTGRID meeting in KIT (Karlsruhe, Germany)

The 6M consortium meeting of FASTGRID has been taken place on the 15th-16th of May in Karlsruhe (Germany) hosted by the KIT (Karlruhe Insititute of Technology).

Participants have discussed scientific activities such as Advanced and emerging REBCO Tapes, Long legth REBCO tapes for demostration and Functionalized material for devices for FCL module.

From ICMAB: X. Obradors (WP1 coordinator), X. Granados,  C. Pop and M. Tristany  have been participated.

Welcome to Mateusz!

Hello, I’m Mateusz [Ma-te-oosh], a former PhD student at the MULFOX group at ICMAB. After graduation I have joined the SUMAN group and now I work on ferroelectric solar cells under the scientific supervision of dr. Mariona Coll

The superconducting materials on betevé television, with Teresa Puig

The TV program Verd Primera, from betevé, has emitted on May 8th, a short video report on superconducting materials.

Teresa Puig explains that these materials have a great potential in terms of energy efficiency.

To know how the superconducting materials are produced, their main characteristics, and their fields of application, don’t miss the video below!

Thanks to Teresa Puig, Susagna Ricart, Flavio Pino and Bohores Villarejo to make this video possible!

Link video fullpage:  https://btv.playty.com/player#/video?autoplay=1&id=VRD080517REPORTATGE

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