X-ray and neutron scattering studies of the complex compounds

Wednesday, September 25, 2013 - 1:00pm

Presented by Dr. Hoyoung Jang, Max Planck Institute for Solid State Research in Stuttgart, Germany

In condensed matter physics, in particular a field of complex oxide materials, most of the research-activity is focusing on finding a new functionality in materials as well as its understanding. In this fashion, during past few decades, many kinds of strongly correlated electronic systems, such as high temperature and unconventional superconductors, colossal magnetoresistance, multiferroics, and heterostructures, have been studied. Meanwhile, the scattering studies on such systems are regarded as being essential. This is because the scattering technique can utilize a long-range order of degrees of freedom (i.e., spin / orbital / lattice / charge) in the strongly correlated system, revealing a ground state.

In this talk, I would like to introduce two examples about the scattering studies on complex ordered materials. For these studies, both x-ray and neutron scattering measurements were employed – resonant elastic x-ray scattering and inelastic neutron scattering. The first example is about the resonant elastic soft x-ray scattering on TbMnO3 system that is a prototype of spiral magnetic ordered multiferroics. By using linearly and circularly polarized light in the ferroelectic state, we revealed the canted cycloidal Mn moment.  The second example is about the antiferromagnetic and antiferro-quadrupolar ordered heavy fermion CeB6. Using the inelastic neutron scattering, we studied the complex low temperature phase of CeB6. As a result, ferromagnetic interaction in CeB6 was revealed and motivated the rethinking of underlying nature of this material. In addition to these examples, experiments on several oxide materials will be introduced.

In condensed matter physics, in particular a field of complex oxide materials, most of the research-activity is focusing on finding a new functionality in materials as well as its understanding. In this fashion, during past few decades, many kinds of strongly correlated electronic systems, such as high temperature and unconventional superconductors, colossal magnetoresistance, multiferroics, and heterostructures, have been studied. Meanwhile, the scattering studies on such systems are regarded as being essential. This is because the scattering technique can utilize a long-range order of degrees of freedom (i.e., spin / orbital / lattice / charge) in the strongly correlated system, revealing a ground state.

In this talk, I would like to introduce two examples about the scattering studies on complex ordered materials. For these studies, both x-ray and neutron scattering measurements were employed – resonant elastic x-ray scattering and inelastic neutron scattering. The first example is about the resonant elastic soft x-ray scattering on TbMnO3 system that is a prototype of spiral magnetic ordered multiferroics. By using linearly and circularly polarized light in the ferroelectic state, we revealed the canted cycloidal Mn moment.  The second example is about the antiferromagnetic and antiferro-quadrupolar ordered heavy fermion CeB6. Using the inelastic neutron scattering, we studied the complex low temperature phase of CeB6. As a result, ferromagnetic interaction in CeB6 was revealed and motivated the rethinking of underlying nature of this material. In addition to these examples, experiments on several oxide materials will be introduced.

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