Unconventional magnetism and electronic state in the frustrated layered system PdCrO2

First-principles calculations and a model consideration of magnetically frustrated layered material ${\mathrm{PdCrO}}₂$ are performed. The results on the exchange parameters are in agreement with the experimental data on the Curie-Weiss temperature ($\ensuremath{\theta}$). We show that experimentally observed strong suppression of the N\'eel temperature (${T}_N$) 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 ${120}^{\ensuremath{\circ}}$ magnetic structure is crucial to provide finite ${T}_N$ value. However, these two factors are still insufficient to explain low ${T}_N$ and the large frustration factor $|\ensuremath{\theta}|/{T}_N$. Thus, we suggest a scenario of an exotic non-Fermi-liquid state in ${\mathrm{PdCrO}}₂$ above ${T}_N$ within the frameworks of the Anderson lattice model, which seems to explain qualitatively all its main peculiarities.