Speaker
Prof.
Stephen Dugdale
(University of Bristol, UK)
Description
Geometrically frustrated magnetic materials exhibit complex magnetic order
and the influence of this frustration (amongst localised spins)
on the more delocalised electrons can lead to strongly correlated behaviour.
The triangular antiferromagnet PdCrO$_{2}$
is an example of a frustrated metallic
magnet. Having the delafossite structure (which consists of alternately
stacked layers of Pd and Cr triangular lattices), the Cr spins are expected to order in a 120$^{\circ}$ spin structure with a $\sqrt{3} \times \sqrt{3}$
periodicity below the N\'eel temperature of 37.5 K.
A study of the paramagnetic Fermi surface of PdrO$_{2}$ will be presented,
based on experimental measurements using Compton scattering in conjunction
with first-principles electronic structure calculations. These results will
be discussed in the context of measurements made in the low temperature
antiferromagnetic phase by angle-resolved photoemission and the
de Haas-van Alphen effect.
