Magnetic structure of the conductive triangular-lattice antiferromagnet PdCrO2

Abstract

We performed neutron single crystal and synchrotron X-ray powder diffraction experiments in order to investigate the magnetic and crystal structures of the conductive layered triangular-lattice antiferromagnet PdCrO2 with a putative spin chirality, which contributes to an unconventional anomalous Hall effect. We revealed that the ground-state magnetic structure is a commensurate and nearly-coplanar 120• spin structure. The 120• plane in different Cr layers seem to tilt with one another, leading to a small non-coplanarity. Such a small but finite non-coplanar stacking of the 120• planes gives rise to a finite scalar spin chirality, which may be responsible for the unconventional nature of the Hall effect of PdCrO2.

Magnetic frustration and spontaneous rotational symmetry breaking in PdCrO2

“…It lifts rotational symmetry in the same way and gives only a marginally worse match to the reflection intensities reported in Ref. [11] (we quantify this statement later), so for discussion we refer to this structure for now and explain possible refinements later. The rotational symmetry breaking appears in two aspects of the structure: the spins lie in the yz plane, and from plane to plane the magnetic order shifts along the y axis, as indicated by the blue dashed line in the figure.…”

“…The nonmagnetic unit cell contains three layers: the offset of the Cr layers with respect to each other introduces an ABCABC stacking. The √ 3 × √ 3 reconstruction associated with 120 • magnetic order is observed in quantum oscillation [5,13], angle-resolved photoemission [12,14], and neutron data [4,11]; early signs of it appear at ∼60 K [15]. The neutron data also suggest a doublek magnetic structure (where k is a propagation vector of the magnetic structure), with simultaneous ferroic and antiferroic interplane correlations.The study of Takatsu et al (Ref.…”

“…(b) A magnetic structure that gives a good fit to the 58 scattering intensities reported in Ref. [11]. The spins lie in the yz plane, and are colored by orientation.…”

“…By analogy with solid oxygen and a related compound, CuCrO 2 [10], this could through a spontaneous rotational symmetry breaking and associated structural distortion that relieves interlayer frustration. However so far no structural distortion has been detected in PdCrO 2 [6,11].It is an important point to resolve, to understand the mechanisms by which magnetic order condenses on frustrated lattices, and here we take a different approach: using symmetry-breaking fields to polarize domains, if they are present. We employ neutron scattering measurements under in-plane uniaxial stress and magnetic field, and resistivity measurements under uniaxial stress.…”

High-throughput search of ternary chalcogenides for p-type transparent electrodes

“…Obviously, there are many more entries ABX 2 with X = O, S, Se, Te in the materials project database (463 in total at the time of writing), but most of these, such as, e.g., the chalcopyrites, have atomic arrangements very different from the delafossites, and do not appear therefore as a result of our search. We could also find in literature some (unfortunatley incomplete) information on other compounds that are not part of the materials project database: MgNiO 2 , PdCrO 2 4546, PdRhO 2 46, KBiS 2 47, KScS 2 48, KYS 2 48, RbScS 2 48, AgRhS 2 49, AgYS 2 50, HgTiS 2 51, TlMnS 2 52, TlMnSe 2 52, KCrSe 2 53, CsBiTe 2 54, TlYTe 2 55. The fact that we also identify these compounds as thermodynamically stable is another confirmation of the validity of our approach.…”