カイラル磁性体における磁気スキルミオン格子構造の安定化

研究了两种手性材料Cu2OSeO_3(铁磁Skyrmion)和CaBaCo2FeO_7(反铁磁性Skyrmion候选)对Skyrmion晶格稳定性的影响。证明了稳定Cu2OSeO_3中Skyrmion晶格的过程依赖于温度和外加温度的历史和速率。此外，还发现了更高阶峰的迹象。发展了一种新的方法，并成功地将其从二次散射中识别出来。手稿已经准备好，预计将于今年晚些时候发布。对更详细效果的追求导致了仪器台康J-PARC数据简化的改进。应用Cu2OSeO_3的分析技术，有助于识别电流对MnSi中Skyrmion晶格的影响。完成了对CaBaCo2Fe2O7一般磁性的研究。用中子散射法分离出两种有序，一种是近程有序，一种是长程有序。第一个模型可以用海森堡近邻模型来描述。然而，后者显示了长周期自旋结构的额外前驱，这确实被对称性分析发现是有利的。另一项中子实验显示，长程有序是在AFM相的大范围内共存的两个周期结构的叠加。虽然较长的周期结构在较低的温度下消失，但剩余的调制类似于天空米子晶格的自旋结构。关于这些特征的手稿正在准备中。然而，一项关键的实验计划被推迟了。

The investigation of the stabilization of skyrmion-lattice was focused on two chiral materials: Cu2OSeO3 (ferromagnetic skyrmion), and CaBaCo2FeO7 (candidate for antiferromagnetic skyrmion). The dependence on the history and rate of temperature and field application when stabilizing the skyrmion-lattice in Cu2OSeO3 was evidenced. Furthermore, indications for higher order peaks were discovered. A new method was developed and applied successfully to discern these from double scattering. A manuscript has been prepared and can be expected later this year. The pursuit of more detailed effects lead to an improvement of the data reduction at the instrument TAIKAN, J-Parc. Applying the analysis techniques for Cu2OSeO3 helped discerning the impact of electric current on the skyrmion lattice in MnSi.The study of the general magnetic properties of CaBaCo2Fe2O7 was completed. Two types of order were separated using neutron scattering, a short range and a long range one. The first one is describable by a Heisenberg nearest neighbor model. Yet, the latter one shows additional precursors of a long-periodic spin structure, which were indeed found favorable using symmetry analysis. Another neutron experiment revealed the long range order to be a superposition of two periodic structures coexisting in a wide range of the AFM phase. While the longer periodic structure vanishes at lower temperatures, the remaining modulation resembles a skyrmion-lattice like spin structure. A manuscript on these features is in preparation. A key experiment was scheduled however postponed.