Possible stress-induced commensurate-to-incommensurate transition in the triangular antiferromagnet PdCrO₂

Antiferromagnetically interacting Heisenberg spins on a 2D triangular lattice generally order into a commensurate 120-degree phase below the Néel temperature. PdCrO₂ is one such material. In our work, we study PdCrO₂, in a piezo-actuated uniaxial stress cell, to probe the response of triangular antiferromagnetism to anisotropic lattice distortion. At a compression of about 0.4%, we find strong signatures of a first order transition in resistivity, magnetoresistivity and Hall effect, which may indicate a commensurate-to-incommensurate transition.