FUNMAT research activities on
Advanced Oxides

Contents

Short description of research fields

Advances and novelties in fields such as energy conversion (batteries, fuel cells), electronics, communication technologies, nanotechnology, biocompatibility, etc. are to a large extent related to new and improved oxidic materials. Many recent scientific breakthroughs in terms of novel physical properties are correspondingly made with oxides, e.g., high temperature superconductivity and giant magnetoresistance.

Norway holds a relatively strong position and contributes significantly in several fields of research on oxidic materials. This is anchored in the traditions of groups and personalities within inorganic and solid state chemistry, electrochemistry and geochemistry/mineralogy, mainly in Oslo and Trondheim. These span back some 100 years, and came partly as a result of the growth of metallurgical industry based on the availability of numerous ores and hydroelectric power and the need for refractories and mineralogical, chemical and electrochemical expertise.

The FUNMAT activities cover ceramic technology, materials synthesis, structural chemistry and physics, thermodynamics, catalysis, defect chemistry, superconductivity, ionic conductivity, proton conduction, corrosion protection, magnetooptics and magnetic properties, piezoelectrica, microporosity, nanosized materials, thin film growth, membranes, in-situ studies, DFT calculations, etc. The focus on basic research is directed towards areas with high potential for novel applications – mostly single phase materials with particular physical properties. This requires competence in synthesis (precision of chemical composition, purity) and fabrication (density, microstructure). Oxide materials achieve large attention in the national materials research program.

With respect to excellence and critical mass, FUNMAT will point at the following fields (web-links will be established to the mentioned topics):
Perovskite-related oxides host recent discoveries related to high temperature superconductivity, giant magneto-resistance, ionic conductivity, oxyhydrides and hybrid oxides, charge and orbital ordering. FUNMAT has strong activities on synthesis of modified or new oxides, in particular reduced oxides obtained by low oxygen partial pressures or strongly reactive environments (metal getter; hydride). Structure determination as such, and as function of temperature, pressure, atmosphere is crucial for structure-property considerations. State-of-the art home XRD laboratory, excellent access to high-resolution powder XRD at the Swiss-Norwegian Beam Lines at ESRF and high resolution powder neutron diffraction at the Kjeller reactor (instrument PUS), provides the required means to determine minor symmetry changes and positions of light and heavy elements with high degree of precision. EXAFS is used in combination with diffraction for local structure/displacement descriptions. Mechanical characterization and studies of ferroelastic perovskites.
Proton conducting oxidic materials are intermediate temperature inorganic proton conductors with potential applications in fuel cells and gas processing. High expertise in defect chemistry and studies of transport phenomena, combines in FUNMAT with activities searching for novel, improved materials.
Mixed conducting oxides, stability. are important for gas separation membranes, novel solid oxide fuel cell anodes and catalysts, all for use under reducing conditions. The required high density, high fracture toughness and creep resistance in these applications have motivated our research on the sintering properties and mechanical properties. In addition to the general knowledge described for perovskite-related oxides above, FUNMATs activities in electrochemistry and thermodynamics provides the required basis for understanding mass transport as well as phase relations between solid-solution components of the fabricated systems. Surface kinetics is essential in the advances of catalysis and use of membranes for gas separation and in fuel cells.
Sensor, imaging and actuator oxides. In connection with the national microtechnology initiative, several activities in FUNMAT are targeted towards bulk or thin film materials for sensors (chemical sensor, partial pressure), imaging (MOI) or actuators.
Cation diffusion and kinetic demixing is of high importance for the lifetime of oxides in high temperature applications and has more recently attracted attention among the FUNMAT research activities.
Thin films and nanoscopic microstructures define the ground for miniaturisation as well as for the possibility of designing entirely new materials properties. Polycrystalline or oriented single crystalline films are made by ALCVD, LPE, sputtering and sol-gel methods. Of high interest is hybrid materials, multilayer systems (purely inorganic as well as hybrid type), piezoelectric films and Magneto-Optical-Imaging (Faraday or Kerr rotation) films.
In-situ studies of oxides at operating conditions. In-situ XRD methods are developed for studying the behaviour of ionic (mixed) conducting oxides and of redox reactions at high temperatures in different atmospheres. This also includes studies of working membranes under large gradients in oxygen partial pressure.
Theory and modelling includes many levels, from quantum chemistry and physics, via understanding of electronic phenomena and aspects related to nano-dimensions, to ionic transport and macroscopic behaviour of materials and fluxes in real processes. Of particular interest is proper description of local ordering and disorder on the oxygen sublattices of complex oxides.

Several of the themes overlap with others within and outside FUNMAT, energy, nano- and micro-technology, catalysis, etc. Nevertheless, the science and applications arising from interactions between oxygen and metals are both unique and rich enough to become a dedicated part of FUNMAT in Norway and materials science in general.

Relevant publications

Perovskite-related oxides

Proton conducting oxidic materials

Mixed conducting oxides, stability

Sensor, imaging and actuator oxides

Thin films and nanoscopic microstructures

In-situ studies of oxides at operating conditions

Theory and modelling

Staff and laboratories

Permanent staff (professors, associate professors, scientists)

Post docs

Phd-students