SQUID-Magnetometer

• Subject Area: Particles, Nuclei and Fields
• Term: Funded in 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 50357144

As already mentioned in section I, the research program of the Arbeitsgruppen of the II. Physikalische Institute is focussed on materials and thin films with strong electron correlation effects. In these systems, magnetism and magnetic correlations play a major role, either directly or indirectly, for phenomena such as metal-insulator and spin-state transitions, anomalous metallic states and non-Fermi liquid behavior, unconventional superconductivity, as well as charge, spin and orbital ordering. Knowledge about the magnetic susceptibility is hereby crucial: (1) it gives a critical characterization about the quality of the synthesized samples including thin films, (2) it forms the necessary basis for further research using techniques such as optical, x-ray and electron spectroscopies, and (3) it provides invaluable information for the interpretation and theoretical modeling of the material properties.Recently, we have successfully extended our Sonderforschungsbereich (SFB) about 'Komplexe Übergangsmetallverbindungen mit Spin- und Ladungsfreiheitsgraden und Unordnung' and our project within the Schwerpunktprogramm (SPP) 1166 about 'Lanthanoidspezifische Funktionalitäten in Molekül und Material'. The projects of these research programs involves heavily (1) the synthesis of new materials including thin films, (2) measurement of the properties by means of magnetic, transport, thermodynamic and spectroscopic methods, and (3) theoretical modelling of the material properties. The success of these research programs put a severe high demand for magnetic susceptibility measurements. To be specific, this demand comes not only for joint projects of the Lehrstuhl für Angewandte Physik (Tjeng, Abd-Elmeguid) and Lehrstuhl für Experimental Physik (Freimuth, Lorenz, Braden) of the II. Physikalisches Institut, but also for those projects of the Anorganische Chemie (Meyer, Möller) and Kristallographie (Bohaty).

• DFG Programme: Major Research Instrumentation
• Instrumentation Group: 0140 Magnetfeld- und -flußmeßgeräte (außer Geomagnetik 040)
• Applicant Institution: Universität zu Köln
• Leaders: Professor Dr. Axel Freimuth; Professor Dr. Liu Hao Tjeng