- 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
- Download Statistik700
- 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.
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