Preparation, characterization and properties of non-molecular solids

The group established by Prof. Alario-Franco back in 1973 has been qualified as "excellent" in 2018 by the Spanish Research Agency. Along this period, the focus has been the synthesis, structure and microstructure of materials in the search of outstanding physical-chemical properties. The main research lines include: study of magnetic/magnetocaloric compounds, superconductors, multiferroics, electrodes and electrolytes of batteries, supercaps and SOFCs. The group benefits from visits of scientists and actively collaborates with other prestigious national/international researchers. Regarding experimental aspects such as the synthesis, the group has expertise in alternative methods, being pioneer in high pressure/high temperature methods, also called "extreme conditions" through the unique "High-Pressure UCM Lab". The group has also pioneered in Spain the microstructural characterization of solids by means of Transmission Electron Microscopy and ancillary techniques along with late Atomic Resolution HRTEM and STEM having the instrumental facilities at the UCM. The group has expertise in transport measurements and frequent access to neutron diffraction and synchrotron facilities is granted. Currently, the group is composed by 21 researchers, including the permanent staff, postdocs and PhD students. The scientific output of the group in the last 5 years includes more than 120 research papers in indexed journals, 3 patents, over 500 communications at conferences and 10 PhD Theses.

The Project is focused on the preparation and structural, electrical and electrochemical characterization of materials as symmetrical electrodes for SOFCs (solid oxide fuel cells) and SOECs (solid oxide electrolysis cells). Studies on perovskites REBaCo2-xMxO5+y (RE= rare earth element; M= transition metal) have demonstrated their excellent properties as electrodes for SOFCs or SOECs (1). These oxides are mixed (electronic and ionic) conductors and the layered-ordering of RE and Ba and specific location of the anion vacancies within the crystal structure play an essential role in their ion-conducting properties.<br />We have studied the properties of GdBaCo2-xMxO5+y (M= Mn, Fe) systems as air electrodes for intermediate temperature SOFCs (2). We have demonstrated that the ordering effects highly impact the crystal structure and properties of these perovskites. For determining the crystal structure of the materials, we use high resolution transmission and scan-transmission electron microscopy methods (HRTEM and STEM). Combining STEM (high angle dark field and bright field) and EELS, we completely solve the crystal structure, locating the different atoms and the anion vacancies with atomic resolution within the structure. Our proficient expertise in the use of these techniques allowed us to solve complex crystal structures and established the strong relations between composition, crystal structure and properties (2, 3). The study of new systems by means of a thorough selection of the type of atoms, leading to a wide combination of ordering effects and properties, is proposed in this Project. <br />1. J. Mater. Chem. A, 2015, 3, 24195; Nat. Mater., 2015, 14, 205"209.<br />2. J. Mater. Chem. A, 2017, 5, 12550; J. Mater. Chem. A, 2018, 6, 5452.<br />3. J. Mater. Chem. A, 2016, 4, 10241.<br />

- CV<br />- Two recomendation letters<br />- Letter of the candidate comenting his/her CV and scientific interests