Heitjans group – Institute of Physical Chemistry and Electrochemistry

MOBILITY OF IONS IN SOLIDS

The Heitjans working group was dedicated to the topics of mobility, diffusion, microdynamics and transport of ions in solids within the framework of a Lower Saxony professorship awarded to the holder after his retirement as professor of physical chemistry.

Meet Prof. Heitjans

List of Publications

Equipment

RESEARCH PROFILE

The research topics are initially aligned with the key themes of the DFG research group FOR 1277 Mobility of Lithium Ions in Solids (molife), which was initiated by the working group. Basic research questions addressed here, such as the influence of structural disorder and low-dimensionality on diffusivity and ion conductivity or the causes of extremely fast or slow transport of ions in different solids (crystalline, nanocrystalline, glassy, nanoglassy), also represent a highly attractive area of basic solid-state research, especially solid-state electrochemistry, in the long term.

Research topics
Phenomena and Properties
dynamical and kinetic processes in solids
diffusion and transport phenomena on atomic scale
local atomic and electronic structure in solids, local disorder effects
interfaces in solids
defect properties
dimensionality of ionic motion (hexagonal vs cubic LixTiS2: 2D vs 3D)
mechanochemical phenomena
heterogeneous catalysis
mixed alkali effect in glasses

Materials
nanocrystalline materials, ceramics, composite materials (CaF2, Li2O:X2O3 (X = Al, B), etc.)
glassy and crystalline ionic conductors (LiNbO3, lithium alumosilicates, etc.)
intercalation compounds, layered structures (Li3N, hexagonal and cubic LixTiS2, LiC6, etc.)
intermetallic compounds (LiAl, etc.)
monoconducting polymer electrolytes
photocatalysts (TiO2)

Methods
nuclear magnetic resonance (NMR) spectroscopy:
spin-lattice relaxation in laboratory and rotating reference frames
lineshape analysis
static and pulsed field gradient spectroscopy (SFG/PFG)
spin-alignment echo (SAE) NMR for the detection of ultra-slow Li motions
β-radiation detected NMR (β-NMR) after neutron capture
AC impedance spectroscopy in the low-frequency and radiofrequency regime
quasi-elastic neutron scattering (QENS)

Sample Characterization
X-ray diffraction (XRD)
scanning electron microscopy (SEM)
transmission electron microscopy (TEM)
differential thermoanalyis (DTA)
infrared spectroscopy (IR)
surface area analysis by nitrogen adsorption
Previous and current cooperation partners
Institute for Theoretical Physics, University of Giessen
Institute for Solid State Research, Forschungszentrum Jülich
Berlin Neutron Scattering Center, Hahn-Meitner-Institut Berlin
Institute of Mineralogy, University of Hannover
Institute for Technical Chemistry, University of Hanover Working Group Prof. Dr. D. Hesse
Institute of Energy Technology, Technical University Berlin
German Institute for Rubber Technology, Hanover
Institute of Physical Chemistry, University of Münster
Materials Group, Dept. Physics, University of Wales, Aberystwyth, UK Dr. R. Winter. Prof. Dr. N. Greaves
Institute for Inorganic Chemistry, University of Kiel Working Group Prof. Dr. W. Bensch
Institute for Inorganic Chemistry, University of Hannover Working Group Prof. Dr. M. Binnewies
Institute for Theoretical Chemistry, University of Bonn Working Group PD Dr. T. Bredow
Institute for Physical Chemistry, University of Braunschweig Working Group Prof. Dr. K. D. Becker
SERC Daresbury Laboratories, UK, Dr. A. Dent.
Institute of Physical Chemistry, RWTH Aachen University Prof. Dr. M. Martin, Dr. R. De Souza
Chair of Technical Chemistry, Ruhr-Universität Bochum Prof. Dr. W. Grünert