Profile

At the institute for Quantum Materials and Collective Phenomena, we focus on the investigation of structural and magnetic order, fluctuations and excitations in complex or nanostructured magnetic systems and highly correlated electron systems. Our research is directed at obtaining a microscopic atomic understanding based on fundamental interaction mechanisms and relating this microscopic information to macroscopic physical properties and functionalities.

The systems studied have a high potential for applications in future information technologies. In the field of nanomagnetism and spintronics, they range from magnetic molecules, via magnetic nanoparticles and magnetic thin film systems to laterally patterned superlattices. Among the correlated electron systems, we focus on transition metal oxides and -chalcogenides with unusual properties, such as colossal magnetoresistance or multiferroicity. Transition metal oxide superlattices, also laterally patterned, combine the aspects of correlated electron systems and nanomagnetism. Thermoelectric materials are being explored in the form of bulk and nanostructures.

Our emphasis lies in the application of most advanced synchrotron X-ray and neutron scattering methods. We place great emphasis on the complementary use of these two probes. Some of our efforts are devoted to dedicated sample preparation, from the synthesis of nanoparticles via physical thin film deposition techniques to single crystal growth. For sample characterization, several ancillary techniques such as magnetometry, specific heat, conductivity etc. are being used to complement the scattering methods.

A significant part of our activity is devoted to the development of novel scattering techniques and the construction and continuous improvement of instruments at large scale neutron and synchrotron radiation facilities. Our strength lays in polarization analysis techniques. The institute for Quantum Materials and Collective Phenomena is part of the Jülich Centre for Neutron Science JCNS, which operates instruments at leading facilities worldwide: the research reactor FRM II in Garching, the Institut Laue-Langevin ILL in Grenoble, France and the Spallation Neutron Source SNS in Oak Ridge, USA. Moreover, we contribute to the operation of a sector at the Advanced Photon Source APS (Argonne, USA). All instruments are accessible via a peer-review system to external users.