Tuning functional properties by strain and doping in oxide thin films for energy applications
Speaker:
Carmela Aruta,
Senior Research Scientist
National Research Council, CNR-SPIN
Rome, Italy
Carmela Aruta is Senior Research Scientist at National Research Council, CNR-SPIN in Rome, Italy. She was post-doc at European Synchrotron Radiation Facility (ESRF) in Grenoble (France), then a tenure track researcher at CNR in Naples. Since 2006 staff researcher at CNR-SPIN: first in Naples, where she was in charge of the pulsed laser deposition system with in-situ AFM and photoemission spectroscopy in the MODA (Modular Facility for Oxide Deposition and Analysis) and the x-ray diffraction laboratory. Then in Rome, where held the position of Deputy Director. She was representative of the Electronic Structure and Magnetism community in the Users’ Organization of ESRF. Member of the Review Committee of ESRF for the Hard Condensed Matter area (2010-2012). She is expert of deposition of thin films and multilayers and their characterization of structural and electronic properties with both laboratory and synchrotron radiation facilities. Her research activity has been mainly devoted to the study of novel phenomena arising at the interfaces of 2D layers, thin films and multilayers with different functional properties for energy applications. The scientific activity is reported in more than 140 papers on peer reviewed International journals and by numerous oral presentations, invited and seminars in international conferences, workshops and foreign research Institutes and Universities. Chair, organizer and member of the scientific committee of many conferences and workshops on functional materials.
Education:
B.S., Physics, 1992, University of Naples Federico II, Italy
Ph.D., Physics, 1999, University of Naples Federico II, Italy
Abstract:
With the increasing demand for renewable and clean energy, electrochemical energy storage/conversion systems, such as hydrogen energy related devices, are gaining greater and greater importance for the reduction of fossil fuel emissions and the production of sustainable fuels and chemicals. In this context, the functional properties caused by mobile oxygen ions in solid oxide materials are deeply investigated. New possibilities in thin film fabrication allow the growth of oxide thin films with a more precise control of the structure and chemical stoichiometry, unveiling new perspectives in the study of technologically important properties of oxide materials and raising the question of whether by using epitaxial thin films the functionalities based on mobile oxygen ions can be properly tuned. In this context, two main class of materials, namely fluorites and perovskites are considered. Among the fluorites, ceria based materials are well known for the plethora of energy applications. The surface reaction activities are essentially described in terms of the efficacy of the metal ions as active sites which bind the reaction intermediates neither too strongly nor weakly. However, our x-ray spectroscopic characterizations reveal how the doping affects the electronic properties, mainly the electronic band structure, which in turn influences the oxygen exchange surface reaction and oxygen ion conductivity. Among the perovskites, we will discuss the case of cobalt oxide thin films where the ionic and electrochemical phenomena are tuned by strain and doping. The band approach and the 3d level electronic occupation can be used to explain the transport and surface reaction properties relevant for energy applications, such as water splitting-based devices or solid oxide fuel cells