Physical properties and electronic structure of Sr$_2$Cr$_3$As$_2$O$_2$ containing CrO$_2$ and Cr$_2$As$_2$ square-planar lattices

Hao Jiang; Jin-Ke Bao; Hui-Fei Zhai; Zhang-Tu Tang; Yun-Lei Sun; Yi Liu; Zhi-Cheng Wang; Hua Bai; Zhu-An Xu; Guang-Han Cao

doi:10.1103/PhysRevB.92.205107

paper

Physical properties and electronic structure of Sr $_{2}$ Cr $_{3}$ As $_{2}$ O $_{2}$ containing CrO $_{2}$ and Cr $_{2}$ As $_{2}$ square-planar lattices

arXiv:1508.01371 · doi:10.1103/PhysRevB.92.205107

Abstract

We report the physical properties and electronic structure calculations of a layered chromium oxypnictide, Sr $_{2}$ Cr $_{3}$ As $_{2}$ O $_{2}$ , which crystallizes in a Sr $_{2}$ Mn $_{3}$ As $_{2}$ O $_{2}$ -type structure containing both CrO $_{2}$ planes and Cr $_{2}$ As $_{2}$ layers. The newly synthesized material exhibits a metallic conduction with a dominant electron-magnon scattering. Magnetic and specific-heat measurements indicate at least two intrinsic magnetic transitions below room temperature. One is an antiferromagnetic transition at 291 K, probably associated with a spin ordering in the Cr $_{2}$ As $_{2}$ layers. Another transition is broad, occurring at around 38 K, and possibly due to a short-range spin order in the CrO $_{2}$ planes. Our first-principles calculations indicate predominant two-dimensional antiferromagnetic exchange couplings, and suggest a KG-type (i.e. K $_{2}$ NiF $_{4}$ type for CrO $_{2}$ planes and G type for Cr $_{2}$ As $_{2}$ layers) magnetic structure, with reduced moments for both Cr sublattices. The corresponding electronic states near the Fermi energy are mostly contributed from Cr-3 $d$ orbitals which weakly (modestly) hybridize with the O-2 $p$ (As-4 $p$ ) orbitals in the CrO $_{2}$ (Cr $_{2}$ As $_{2}$ ) layers. The bare bandstructure density of states at the Fermi level is only $\sim$ 1/4 of the experimental value derived from the low-temperature specific-heat data, consistent with the remarkable electron-magnon coupling. The title compound is argued to be a possible candidate to host superconductivity.

10 pages, 9 figures

Physical properties and electronic structure of Sr $_{2}$ Cr $_{3}$ As $_{2}$ O $_{2}$ containing CrO $_{2}$ and Cr $_{2}$ As $_{2}$ square-planar lattices

Abstract

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Cited by in corpus (18)

Physical properties and electronic structure of Sr2​Cr3​As2​O2​ containing CrO2​ and Cr2​As2​ square-planar lattices

Abstract

References in corpus (21)

Cited by in corpus (18)

Physical properties and electronic structure of Sr $_{2}$ Cr $_{3}$ As $_{2}$ O $_{2}$ containing CrO $_{2}$ and Cr $_{2}$ As $_{2}$ square-planar lattices