Unconventional magnetism and electronic state in the frustrated layered system PdCrO2

Abstract

First-principles calculations and a model consideration of magnetically frustrated layered material PdCrO 2 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 (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 • 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 |θ|/T N. Thus, we suggest a scenario of an exotic non-Fermi-liquid state in PdCrO 2 above T N within the frameworks of the Anderson lattice model, which seems to explain qualitatively all its main peculiarities.

Magnetic and electronic ordering phenomena in the [Ru$_2$O$_6$] honeycomb lattice compound AgRuO$_3$

“…wave theory can be used to estimate the Néel temperature according to [47,48]. With calculated intra-and interplane exchange parameters we get T N = 304 K, which is close to experimental 342 K. It should be mentioned that the calculated value of the intraplane exchange constant is also consistent with the Raman spectroscopy results.…”

Magnetic order and electronic transport properties in the Mn3Al compound: The role of the structural state

“…High values of the frustration parameter are observed, for example, in the PdCrO2 compound, where TN = 37 K, θCW ≈ -500 K [24]. This behavior is apparently not described by the standard Heisenberg model and is due to correlation effects in the subsystem of itinerant electrons [25]. A similar behavior of the magnetic susceptibility for the Mn2FeAl compound with the β-Mn structure was recently discovered and compared to the frustrated antiferromagnetism in [14,15] (TN = 42 K, θCW ≈ -230 K according to [15]).…”

Two-band model and RVB-type states: application to Kondo lattices, pyrochlores and Mn-based systems

“…where we have the FL * picture [18]. Such a picture was proposed to treat properties of the frustrated layered system PdCrO 2 [28]. Near the metal-insulator transition, a second crossover (which is connected with condensation of spinons), and even some more crossovers, were proposed [25].…”