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  • Autor
    • Horvat, Alen
    • Pourovskii, Leonid
    • Aichhorn, Markus
    • Mravlje, Jernej
  • TitelTheoretical prediction of antiferromagnetism in layered perovskite Sr2TcO4
  • Datei
  • Persistent Identifier
  • Erschienen inPhysical Review / B
  • Band95
  • Erscheinungsjahr2017
  • Heft20
  • Seiten205115
  • LicenceCC-BY
  • ZugriffsrechteCC-BY
  • Download Statistik401
  • Peer ReviewJa
  • AbstractWe theoretically investigate the magnetic properties of \(Sr_2TcO_4\) , a 4d transition-metal layered perovskite of the \(K_2NiF_4\) type with half-filled \(t_{2g}\) states. The effect of local Coulomb repulsion between the \(t_{2g}\) orbitals is included within the density-functional theory (DFT) + U and DFT + dynamical mean-field theory (DMFT) methods. The DFT + DMFT predicts paramagnetic \(Sr_2TcO_4\) to be close to the Mott insulator-to-metal transition, similarly to the cubic compound \(SrTcO_3\) . The intersite exchange interactions computed within the DFT + DMFT framework point to a strong antiferromagnetic coupling between the neighboring Tc sites within the layer. We then evaluate the Néel temperature \(T_N\) within a classical Monte Carlo approach including dipolar interactions, which stabilize the magnetic order in the frustrated \(K_2NiF_4\) lattice structure. Our approach is validated by applying it to a set of layered and cubic perovskites, for which we obtain \(T_N\) in fair agreement with experiment. Within the same approach we obtain the \(T_N\) of \(Sr_2TcO_4\) to be about 450 K. We explore also the effect of anisotropy in exchange interactions due to spin-orbit coupling. These lead to a somewhat higher transition temperature, 550 K.