Abstract
Sr2Cr3As2O2 is composed of alternating square-lattice CrO2 and Cr2As2 stacking layers, where CrO2 is isostructural to the CuO2 building-block of cuprate high-Tc superconductors and Cr2As2 to Fe2As2 of Fe-based superconductors. Current interest in this material is raised by theoretic prediction of possible superconductivity. In this neutron powder diffraction study, we discovered that magnetic moments of Cr(II) ions in the Cr2As2 sublattice develop a C-type antiferromagnetic structure below 590 K, and the moments of Cr(I) in the CrO2 sublattice form the La2CuO4-like antiferromagnetic order below 291 K. The staggered magnetic moment 2.19(4)μB/Cr(II) in the more itinerant Cr2As2 layer is smaller than 3.10(6)μB/Cr(I) in the more localized CrO2 layer. Different from previous expectations, a spin-flop transition of the Cr(II) magnetic order observed at 291 K indicates a strong coupling between the CrO2 and Cr2As2 magnetic subsystems.
| Original language | English |
|---|---|
| Article number | 134416 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 13 |
| DOIs | |
| State | Published - Oct 10 2018 |
Funding
The work at RUC was supported by the National Basic Research Program of China (Grant No. 2012CB921700), the National Natural Science Foundation of China (Grant No. 11190024), and the Key Laboratory of Neutron Physics, CAEP (Grant No. 2017CB01). J.L. and J.W. acknowledge support from the Research Funds of RUC (Grant No. 17XNLF04 and 17XNLF06). J.S. acknowledges support from China Scholarship Council. The work at Z.U. was supported by the National Key Research and Development Program of China (No. 2017YFA0303002). Research at Oak Ridge National Laboratory was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.