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Uniaxial Pressure Tuning of a Triangular Antiferromagnet
Speaker Dr Dan Sun
Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187
Dresden, Germany
Date 7 July 2017 (Friday)
Time 14:00 - 15:00
Venue Room 4504 (Lifts 25-26), HKUST
Antiferromagnetically interacting Heisenberg spins locating on a triangle lattice, such as those in PdCrO2, generally order into a commensurate 120-degree phase below Neel temperature. In our work, we use a newly developed piezo-actuated strain rig, which is able to apply both positive and negative uniaxial pressure to about 1 GPa, to conduct uniaxial pressure studies on PdCrO2. By cancelling the strain due to the thermal contraction of sample holders, we achieve the true zero strain, and discover a line of first order transition well below Neel temperature. This suggests that further degree of freedom is frozen. Furthermore, we probe the response of the triangular antiferromagnet to anisotropic lattice distortion. At lattice compression of about 0.4%, we find signatures in resistivity, magnetoresistivity and Hall effect, which may indicate a commensurate-to-incommensurate transition.