Name: Thomas Harmening
Diploma / M.Sc degree: Westfälische Wilhelms-Universität Münster, Germany
(February 2007)

PhD Project: ⁴⁵Sc solid state NMR as a local probe for structure determination of intermetallic scandium compounds

Abstract of Research Project

The synthesis and structural investigations of intermetallic scandium-containing compounds are in the focus of the present research project. In order to obtain a comprehensive insight of structural features, high resolution ⁴⁵Sc MAS NMR spectroscopy is used in parallel to single crystal X-ray diffraction (in collaboration with Prof. Eckert).

Ternary intermetallic scandium compounds Sc_xT_yX_z (T = late transition metal; X = main group metal/semimetal) offer a huge and variable class of compounds. Despite the lower atomic radius compared to lutetium, its intermetallic compounds are often isotypic to the corresponding lutetium compounds. In some cases scandium can not fulfil the sterical requirements of a [T_yX_z] polyanion because of its small size. Then either different structures are formed that are rather typical for zirconium and hafnium. Or a superstructure formation occurs whereby the different packing of the polyanion allows an almost similar atomic arrangement to lutetium. Due to the symmetry reduction it may occur that the scandium sites of the subcell are split in the superstructure. In these cases high resolution ⁴⁵Sc MAS NMR can resolve these different positions and therefore prove the superstructure formation. Another advantage of using NMR as a local probe in addition to single crystal X-ray diffraction is the detection and quantification of structural defects.


Publications

T. Harmening, W. Hermes, M. Eul, R. Pöttgen
Mixed valent stannide EuRuSn3 - Structure, magnetic properties, and Moessbauer spectroscopic investigation
Solid State Sci. 12(2) (2010), 284-290.

T. Harmening, L. van Wuellen, H. Eckert, U. C. Rodewald, R. Pöttgen
Sc4Pt7Si2 - An Intergrowth Structure of ScPtSi and ScPt Related Slabs
Z. Anorg. Allg. Chem. 636(6) (2010), 972-976.

T. Harmening, R. Pöttgen
151Eu Moessbauer spectroscopic characterization of EuRu4B4 and the new boride EuRuB4
Z. Naturforsch. 65B (2010), 90-94.

S. Balamurugan, U. C. Rodewald, T. Harmening, L. Van Wuellen, D. Mohr, H. Eckert, R. Pöttgen
Sc2(MoO4)3 and Sc2(WO4)3: Halide flux growth of single crystals and 45Sc solid-state NMR
Z. Naturforsch. 65B (2010), 13-17.

T. Harmening, W. Hermes, M. Eul, F. M. Schappacher, R. Pöttgen
Structure and properties of Eu2Pt3Sn5
Z. Kristallogr. 224(7) (2009), 351-357.

W. Hermes, T. Harmening, R. Pöttgen
Ferromagnetism and Magnetocaloric Effect around 95 K in the Laves Phase EuRh1.2Zn0.8
Chem. Mater. 21(14) (2009), 3325-3331.

W. Hermes, S. F. Matar, T. Harmening, U. C. Rodewald, M. Eul, R. Pöttgen
Ferromagnetic ordering in CeZnSn
Z. Naturforsch. 64B (2009), 175-183.

M. Zeuner, S. Pagano, P. Matthes, D. Bichler, D. Johrendt, T. Harmening, R. Pöttgen, W. Schnick
Mixed Valence Europium Nitridosilicate Eu2SiN3
J. Am. Chem. Soc. 131(31) (2009), 11242-11248.

T. Harmening, A. Al Alam, S. F. Matar, H. Eckert, R. Pöttgen
Structure, chemical bonding, and 45Sc solid state NMR of Sc2RuSi2
Solid State Sci. 11(7) (2009), 1239-1245.

T. Harmening, H. Eckert, R. Pöttgen
Defects in half-Heusler type antimonides ScTSb (T = Ni, Pd, Pt)
Solid State Sci. 11(4) (2009), 900-906.

M. Wolff, T. Harmening, R. Pöttgen, C. Feldmann
Sn3I8•2(18-crown-6): a Mixed-Valent Tin-Crown-Ether Complex
Inorg. Chem. 48(7) (2009), 3153-3156.


Thomas Harmening
eMail: Thomas Harmening