%0 Journal Article
%A Dutta, Rajesh
%T Ab-initio DFT＋ U study on the electronic correlation in multiferroic XY-antiferromagnetic Ba$_2$CoGe$_2$O$_7$
%J Journal of magnetism and magnetic materials
%V 596
%@ 0304-8853
%C Amsterdam
%I North-Holland Publ. Co.
%M FZJ-2024-05292
%P 171955 -
%D 2024
%Z Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
%X Ab-initio density functional theory (DFT)+U has been used to study the spin-resolved electronic band structure and the partial density of states of the multiferroic XY-antiferromagnetic Ba$_2$CoGe$_2$O$_7$. Using the constrained random-phase approximation (cRPA) method, the value of Hubbard U and Hund’s coupling 𝐽H has been determined and plugged into the further dynamical mean field theory (DMFT) calculations. The strong metalligand hybridization between Co-3d and O-2p orbitals in the CoO$_4$ tetrahedron has been demonstrated via DFT and DFT+DMFT calculations. The calculated indirect band gap in the antiferromagnetic state without and with U (=5 eV) correction is found to be 0.67 and 2.71 eV, respectively. The highest calculated ordered magnetic moment of 2.7 𝜇𝐵/Co$^{2+}$ is close to the reported experimental value. The presented DFT calculations based on the different orbital models brings the underlying strong electronic correlation in the Ba$_2$CoGe$_2$O$_7$.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001221007700001
%R 10.1016/j.jmmm.2024.171955
%U https://juser.fz-juelich.de/record/1030419