Itinerant magnetism of chromium under pressure: a DFT plus DMFT study

We consider electronic and magnetic properties of chromium, a well-known itinerant antiferromagnet, by a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT). We find that electronic correlation effects in chromium, in contrast to its neighbors in the periodic table, are weak, leading to the quasiparticle mass enhancement factor m*/m approximate to 1.2. Our results for local spin-spin correlation functions and distribution of weights of atomic configurations indicate that the local magnetic moments are not formed. Similarly to previous results of DFT at ambient pressure, the non-uniform magnetic susceptibility as a function of momentum possesses close to the wave vector Q (H) = (0, 0, 2 pi/a) (a is the lattice constant) sharp maxima, corresponding to Kohn anomalies. We find that these maxima are preserved by the interaction and are not destroyed by pressure. Our calculations qualitatively capture a decrease of the Neel temperature with pressure and a breakdown of itinerant antiferromagnetism at pressure of similar to 9 GPa in agreement with experimental data, although the Neel temperature is significantly overestimated because of the mean-field nature of DMFT.

Automated summary

The electronic and magnetic properties of chromium were studied using a combination of DFT and DMFT, revealing weak electronic correlations and a lack of formation of local magnetic moments. The non-uniform magnetic susceptibility showed sharp maxima at the wave vector Q(H) = (0, 0, 2pi/a), corresponding to Kohn anomalies. These anomalies were preserved by interactions and pressure did not destroy them, leading to a qualitative decrease in the Neel temperature and breakdown of itinerant antiferromagnetism at around 9 GPa.