| Speaker: |
Dr. Simon A.J. Kimber |
| Affiliation: |
ESRF, Grenoble, France |
| Title: |
Fractional excitations and frustration in spin systems |
| Date: |
Tue Dec 7, 2010 |
| Start: |
11.00 |
| Location: |
FWN-Building 5118.-152 |
| Host: |
T.T.M. Palstra |
| Telephone: |
+31 50 363 4419 |
Abstract
Transition metal oxides make up a large and technologically useful class of materials. In this seminar I shall describe how complex behaviour emerges in these materials as a result of local degrees of freedom and long-range interactions. Neutron and X-ray scattering are an ideal probe of the spatial and temporal correlations in these cases, and I will describe two new systems which show counterintuitive behaviour. The first, CoV2O6, is an effective S=1/2 spin chain with fractional excitations, which are confined at low temperatures. The second, Ba3NaRu2O9, is a rare example of a frustrated lattice which shows near integer order of charges, and unusual freezing and melting dynamics.
