Unconventional magnetism and electronic state in the frustrated layered system PdCrO2

First-principles calculations and a model consideration of magnetically frustrated layered material PdCrO2 are performed. The results on the exchange parameters are in agreement with the experimental data on the Curie-Weiss temperature ( θ ). We show that experimentally observed strong suppression of the Néel temperature ( TN ) in comparison with the Curie-Weiss temperature is due to three main factors. First, as expected, this is connected with the layered structure and relatively small exchange interaction along the c axis. Second, deformation of the ideal in-plane 120 ∘ magnetic structure is crucial to provide finite TN value. However, these two factors are still insufficient to explain low TN and the large frustration factor | θ | / TN . Thus, we suggest a scenario of an exotic non-Fermi-liquid state in PdCrO2 above TN within the frameworks of the Anderson lattice model, which seems to explain qualitatively all its main peculiarities.