Former Members of the Güdel Group

Dr. Ralph Schenker;
graduate student until 2001 and postdoc from August 2004 until April 2005

Contact Ralph Schenker, rs.JPG (19 kByte)
Dr. Ralph Schenker
Test and Service CryoProbe
Bruker BioSpin AG
NMR Division
Industriestrasse 26
CH - 8117 Fällanden
Switzerland

Phone +41 (0)44 825 9452
Fax +41 (0)44 825 9404
e-Mail ralph.schenker@bruker-biospin.ch
raschenker@bluewin.ch
Web http://www.bruker.ch

Education

Born 1971.
Matura 1991.
Diploma in Chemistry at the University of Bern 1996, title of diploma thesis: "Synthesis and Optical Spectroscopy of MnO42- doped Crystals".
PhD in Chemistry at the University of Bern 2001; thesis entitled: "Exchance Interactions in Cr3+ and Fe3+ Dimers and in a [(Cr3+)3Ni2+] Tetramer. Optical Spectroscopic, Magnetic, and Inelastic Neutron Scattering Studies."
2001-2004: Postdoc at the Department of Chemistry of the University of Wisconsin-Madison.

Research field

My interest lies in the investigation of the physical properties of exchange-coupled transition metal ion systems. Using polarized single-crystal absorption and emission spectroscopy at variable temperatures, magnetic measurements (SQUID), as well as Inelastic Neutron Scattering (INS), exchange splittings of ground and excited states are determined. (Orbital) Exchange parameters are derived, which allows to determine the relevant orbital exchange pathways.

Publications

H. U. Güdel, T. Brunold, M. Hazenkamp, M. Herren, U. Oetliker and R. Schenker
Luminescence of Transition Metal Ions in Unusual Oxidation States
Electrochem. Soc. Proceedings (Luminescent Materials VI) 97-29, 225-234 (1998)      Abstract      Full Text (PDF)

Ralph P. Schenker, Thomas C. Brunold and Hans U. Güdel
Synthesis and Optical Spectroscopy of MnO42--Doped Crystals of Cs2CrO4, SrCrO4, CsBr and CsI
Inorg. Chem. 37, 918-927 (1998)      Abstract      Full Text (PDF)

Ralph Schenker, Høgni Weihe and H. U. Güdel
Double exchange in the charge-transfer states of [Cr2(OH)3(tmtame)2]3+
Chem. Phys. Lett. 303, 229-234 (1999)      Abstract      Full Text (PDF)

Ralph Schenker, Høgni Weihe and Hans U. Güdel
Exchange Interactions Derived from Electron Transfer Processes in [Cr2(OH)3(tmtame)2](NO3)3
Inorg. Chem. 38, 5593-5601 (1999)      Abstract      Full Text (PDF)

Ralph Schenker, Stephan Heer, Hans U. Güdel and Høgni Weihe
Optical Dimer Excitations and Exchange Parameters in (Et4N)3Cr2F9: First Observation of the 4A2 2A1 Transition
Inorg. Chem. 40, 1482-1488 (2001)      Abstract      Full Text (PDF)

Ralph Schenker, Høgni Weihe, Hans U. Güdel and Berthold Kersting
Exchange Pathways in Tris-m-thiolato Bridged [Cr2L3](CIO4)2CI·H2O·MeOH (L = 2,6-Bis(aminomethyl)-4-tert-butyl-thiophenolate)
Inorg. Chem. 40, 3355-3362 (2001)      Abstract      Full Text (PDF)

Ralph Schenker, Høgni Weihe and Hans U. Güdel
Ferromagnetic Exchange in the Ground state and 4A1 Exited State of (Et4N)3Fe2F9. A Magnetic and Optical Spectroscopic Study
Inorg. Chem. 40, 4319-4326 (2001)      Abstract      Full Text (PDF)

Karl W. Krämer, Ralph Schenker, Jürg Hauser, Høgni Weihe, Hans U. Güdel and Hans-Beat Bürgi
Crystal Structures of (Et4N)3M2F9 (M = V, Cr, Fe) determined by X-Ray Single-Crystal and Powder Diffraction: A New Structure Type for A3M2X9 Compounds
Z. Anorg. Allg. Chem. 627, 2511-2516 (2001)      Abstract      Full Text (PDF)

Ralph Schenker, Myriam Triest, Christian Reber and Hans U. Güdel
Interference Dips in the Single-Crystal Absorption Spectrum of the Tri-m-fluoro-Bis(trifluorochromate(III)) Complex
Inorg. Chem. 40, 5787-5794 (2001)      Abstract      Full Text (PDF)      Supplementary Data (PDF)

Ralph Schenker, Michael N. Leuenberger, Grégory Chaboussant, Hans U. Güdel and Daniel Loss
Butterfly hysteresis and slow relaxation of the magnetization in (Et4N)3Fe2F9: manifestations of a single-molecule magnet
Chem. Phys. Lett. 358, 413-418 (2002)      Abstract      Full Text (PDF)

Ralph Schenker, Høgni Weihe, Hanspeter Andres, Reto Basler, Grégory Chaboussant, Kirsten Michelsen, Michael Aebersold, Herma Büttner and Hans U. Güdel
Competing Interactions in the Tetranuclear Spin Cluster {Ni[(OH)2Cr(bispictn)]3}I5·5H2O. An Inelastic Neutron Scattering and Magnetic Study
Inorg. Chem. 41, 4266-4274 (2002)      Abstract      Full Text (PDF)

new Ralph Schenker, Michael N. Leuenberger, Grégory Chaboussant, Daniel Loss and Hans U. Güdel
Phonon bottleneck effect leads to observation of quantum tunneling of the magnetization and butterfly hysteresis loops in (Et4N)3Fe2F9
Phys. Rev. B 72, 184403/1-10 (2005)      Abstract      Full Text (PDF)

Links

Visit Ralph Schenkers's Photo Gallery at the University of Bern: http://guedel.dcb.unibe.ch/membersold/rs/index.htm

Visit the Department of Chemistry at the University of Wisconsin-Madision: http://www.chem.wisc.edu

Last modified: 13.12.11 by Gabriela Frei