Transition from Pauli paramagnetism to Curie-Weiss behaviour in vanadium

Abstract

We study electron correlations and their impact on magnetic properties of vanadium by a combination of density functional and dynamical mean-field theory. The calculated uniform magnetic susceptibility is of Pauli type at low temperatures, while it obeys the Curie-Weiss law at higher temperatures in a qualitative agreement with experimental data. Our results for local spin-spin correlation function and local susceptibility reveal that the Curie-Weiss behaviour occurs due to partial formation of local magnetic moments. We show that these moments originate from t 2g states and their formation is mainly governed by local spin correlations caused by Hund's rule coupling. The formation of local moments is accompanied by a deviation from the Fermi-liquid behaviour although fermionic quasiparticles remain well-defined. The obtained quasiparticle mass enhancement factor of about 1.5-2 corresponds to a moderately correlated metal. By analyzing the momentum dependence of static magnetic susceptibility, we find incommensurate magnetic correlations which may cause the loss of quasiparticle coherence upon heating.

The effect of local magnetic moments on spectral properties and resistivity near the interaction- and doping induced Mott transitions

“…The damping of the quasiparticles Γ = −ImΣ(0) at intermediate temperatures increases with increasing U and at the temperatures T ∼ T * follows the linear temperature dependence Γ Γ 0 + AT instead of the quadratic one for the Fermi liquid. We note that recently similar linear temperature dependencies of the quasiparticle damping were obtained in the combination of ab initio and DMFT studies of vanadium in the regime of partly formed local magnetic moments [39], albeit in the latter case it is caused by Hund interaction instead of proximity to Mott insulator.…”