2015/11/30 by Stevan Arsenijević, Jong Mok Ok, Peter Robinson +4 · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.116.087202
published as Phys. Rev. Lett. 116, 087202 (2016) · 5 pages and 4 figures in Main text + 4 pages and 5 figures in Supplementary material
arxiv created 2016/02/24 · arxiv updated 2016/02/26
We report the temperature T and magnetic field H dependence of the thermopower S of an itinerant triangular antiferromagnet PdCrO2 in high magnetic fields up to 32 T. In the paramagnetic phase, the zero-field thermopower is positive with a value typical of good metals with a high carrier density. In marked contrast to typical metals, however, S decreases rapidly with increasing magnetic field, approaching zero at the maximum field scale for T > 70 K. We argue here that this profound change in the thermoelectric response derives from the strong interaction of the 4d correlated electrons of the Pd ions with the short-range spin correlations of the Cr3+ spins that persist beyond the Néel ordering temperature due to the combined effects of geometrical frustration and low dimensionality.