Ames National Laboratory, U.S. DOE, Iowa State University, Ames, IA 50011, United States of America.
Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, United States of America.
J Phys Condens Matter. 2023 Jun 29;35(39). doi: 10.1088/1361-648X/ace093.
The magnetic order for several compositions of CaK(Fe1-xMn)Ashas been studied by nuclear magnetic resonance (NMR), Mössbauer spectroscopy, and neutron diffraction. Our observations for the Mn-doped 1144 compound are consistent with the hedgehog spin vortex crystal (hSVC) order which has previously been found for Ni-dopedCaKFe4As4. The hSVC state is characterized by the stripe-type propagation vectors(π0)and(0π)just as in the doped 122 compounds. The hSVC state preserves tetragonal symmetry at the Fe site, and only this SVC motif with simple antiferromagnetic (AFM) stacking alongis consistent with all our observations using NMR Mössbauer spectroscopy, and neutron diffraction. We find that the hSVC state in the Mn-doped 1144 compound coexists with superconductivity, and by combining the neutron scattering and Mössbauer spectroscopy data we can infer a quantum phase transition, hidden under the superconducting dome, associated with the suppression of the AFM transition temperature () to zero for ≈ 0.01. In addition, unlike several 122 compounds and Ni-doped 1144, the ordered magnetic moment is not observed to decrease at temperatures below the superconducting transition temperature ().
通过核磁共振（NMR）、穆斯堡尔光谱和中子衍射研究了 CaK(Fe1-xMn)As 几种成分的磁有序。我们对掺杂 1144 化合物的锰观察结果与之前在掺杂 CaKFe4As4 的镍中发现的刺猬自旋涡旋晶（hSVC）有序一致。hSVC 态的特征是条纹型传播向量(π0)和(0π)，就像掺杂 122 化合物一样。hSVC 态在 Fe 位保持四方对称性，只有这种具有简单反铁磁（AFM）堆叠的 SVC 图案与我们使用 NMR 穆斯堡尔光谱和中子衍射的所有观察结果一致。我们发现掺杂 1144 化合物中的 hSVC 态与超导性共存，通过结合中子散射和穆斯堡尔光谱数据，我们可以推断出与 AFM 转变温度（）抑制到零相关的量子相变，在 ≈ 0.01 下，这与超导转变温度（）下的 AFM 转变温度有关。此外，与几种 122 化合物和掺杂 1144 的镍不同，在超导转变温度（）以下的温度下，未观察到有序磁矩降低。
