Research interests
Studies are mainly focussed on species identification in nanostructured
solid fluorides as well as on the mechanism of their formation. These
solids are either prepared by fluorolytic sol-gel reactions (research
group: Kemnitz) or by mechanochemical synthesis. Ideally, solid state
NMR can be used as powerful analytical tool applicable both for
crystalline, partially crystalline and X-ray amorphous samples.
- Mechanochemistry of inorganic materials
- Local structure of spin probes in solids with coexisting
crystalline and non - crystalline regions
(polycrystalline, partially crystalline, nanostructured, amorphous
matrices)
- Formation and influence of the vapour phase on structural
reorganizations of crystalline and amorphous solids
- Chemically, thermally and mechanically induced reactions of
solids;
- Phase transitions of inorganic solids
Spin probes: 19F, 27Al, 1H, 2H,13C,
(69,71Ga, 115In, 29Si, 25Mg)
Projects:
Solid state NMR studies on the formation of local
structures at fluorolytic sol-gel processes
- Identification and assignment of local species and their
changes with different degree of fluorination
- study of sols, wet gels, xerogels and nanoscopic metal fluorides
- spinning of sols and wet gels up to 12 kHz using home-made
inserts for MAS rotors
Determination of local structures in crystalline and
amorphous fluoride and oxide materials by
solid - state NMR
Mechanochemical synthesis, structure and properties of
nanoscopic metal fluorides and of their solid solutions
(project in the Graduate School GRK-1582- Fluorine as key element)
Mechanochemical synthesis of inorganic - organic hybride
materials on a fluoride basis
Distorted metal oxides by fluoride doping and /or
mechanochemical activation (project C01 in the collaborative
research centre CRC 1109)
Solid state NMR investigations on the formation and
structure of "High-surface" AlF3 - a new highly disordered
AlF3 synthesized on the
sol-gel basis.
DFG-Project KE 489/29-1 (2006 - 2008)
Applicants: Prof. Dr. E. Kemnitz, PD Dr. G. Scholz (HU Berlin), Prof.
Dr. C. Jäger (BAM Berlin),
Methods:
- Preparation of samples by: mechanical milling (planetary mill),
thermal annealing, irradiation;
- Solid - state MAS - NMR
- Calculation of solid state NMR spectra for amorphous and
crystalline solids based on the Spin -Hamiltonian and statistical -
distributions of spin coupling parameters;
- XRD; DTA/DTG
NMR equipment
- 400 MHz solid state NMR spectrometer (Bruker Avance 400)
- Probe heads:
- 2.5 mm (X/1H,19F);
4 mm (X/1H,19F); 4 mm in situ (X/1H,19F); 4 mm, low gamma
(109Ag-15N/1H);
7 mm (X/1H); 7 mm, low gamma, (89Y-17O/1H, 19F)
- N2-generator for spinning of air sensitive samples and low
temperature experiments
Back to mainpage