Analytical and numerical investigations of noncollinear magnetic ordering in the frustrated delafossite CuCrO 2

Ahmed Al Baalbaky (1) , Yaroslav Kvashnin (2) , Renaud Patte (1) , Denis Ledue (1)

1 GPM - Groupe de physique des matériaux
2 ESRF - European Synchrotron Radiation Facility

The magnetic propagation vector in delafossite CuCrO 2 with classical Heisenberg spins is calculated analytically as a function of exchange interactions up to fourth-nearest neighbors. Exchange interactions are estimated by a series of density functional theory calculations for several values of lattice distortion. Our calculations show that the magnetic propagation vector is directly affected by the considered distortions providing different stable commensurate or incommensurate magnetic configurations. A realistic set of exchange interactions corresponding to a 0.1% lattice distortion yields the experimental ground state with an incommensurate propagation vector q ∼ (0.329, 0.329, 0). We find that a very weak antiferromagnetic interlayer interaction favors an incommensurate ordering even in the absence of lattice distortion. Moreover, the exchange energy of a magnetic configuration of a finite crystal of CuCrO 2 with periodic boundary conditions is derived analytically. Based on that, highly accurate Monte Carlo simulations performed on CuCrO 2 confirm both the proposed analytical calculations and the density functional theory estimations, where we obtain excellent convergence toward the experimental ground state with a magnetic propagation vector q = (0.3288, 0.3288, 0).

Domaines: Physique [physics]; Science des matériaux [cond-mat.mtrl-sci]

Ahmed Al Baalbaky, Yaroslav Kvashnin, Renaud Patte, Denis Ledue. Analytical and numerical investigations of noncollinear magnetic ordering in the frustrated delafossite CuCrO 2. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2019, 99 (10), ⟨10.1103/PhysRevB.99.104415⟩. ⟨hal-02106761⟩