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arXiv · 1204.3150

Evaluation of Half-metallic Antiferromagnetism in ${\cal A}_2$CrFeO$_6$ ({$\cal A$}=La, Sr

K. -W. Lee·Kyo-Hoon Ahn
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Abstract

The nearly well-ordered double perovskite La$_2$CrFeO$_6$ has been synthesized recently. Contrary to previous theoretical predictions, but in agreement with experimental observations, our first principle calculations indicate an insulating ferrimagnet La$_2$CrFeO$_6$ with antialigned S=3/2 Cr$^{3+}$ and S=5/2 Fe$^{3+}$ ions,using the local spin density approximation (LSDA), a correlated band theory LDA+U, and a semilocal functional modified Becke-Johnson method. Additionally, we investigated the double perovskite Sr$_2$CrFeO$_6$, which is as yet unsynthesized. In LSDA calculations, this system shows formally tetravalent Cr and Fe ions both having antialigned $S$=1 moments, but is a simple metal. Once applying on-site Coulomb repulsion U on both Cr and Fe ions, this system becomes half-metallic and the moment of Fe is substantially reduced, resulting in zero net moment. These results are consistent with our fixed spin moment studies. Our results suggest a precisely compensated half-metallic Sr$_2$CrFeO$_6$.

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K. -W. Lee, Kyo-Hoon Ahn. 2012-04-14. Evaluation of Half-metallic Antiferromagnetism in ${\cal A}_2$CrFeO$_6$ ({$\cal A$}=La, Sr. https://doi.org/10.1103/physrevb.85.224404

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