Magnetic properties of monolayer, multilayer, and bulk <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>CrTe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math>

Abstract

We investigate magnetic properties of ${\mathrm{CrTe}}_{2}$ within the density functional theory (DFT) approach in ferromagnetic phase and the combination of the DFT and the dynamical mean field theory ($\mathrm{DFT}+\mathrm{DMFT}$) approach in the paramagnetic phase. We show that a few-layer ${\mathrm{CrTe}}_{2}$ possesses well-formed local magnetic moments. In the monolayer ${\mathrm{CrTe}}_{2}$, we find the most preferable antiferromagnetic exchange with the ${120}^{\ensuremath{\circ}}$ antiferromagnetic structure. In the bilayer and trilayer systems, electronic correlations in the $\mathrm{DFT}+\mathrm{DMFT}$ approach yield ferromagnetic exchange interaction within each layer, but the interaction between the layers is antiferromagnetic, such that alternation of the direction of magnetization between the layers is expected. In bulk ${\mathrm{CrTe}}_{2}$ we find the tendency toward ferromagnetic order at low temperature, but with an increase in temperature, antiferromagnetic correlations between the layers dominate. Determination of the critical number of layers at which the interlayer antiferromagnetic order changes to ferromagnetic likely requires consideration of the nonlocal Coulomb interactions.

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