Attention is drawn to a possibility to obtain the monochiral helimagnet MnSi in a magnetic single domain state (SDS) in zero magnetic field limit. It is shown that this metastable zero field magnetic SDS can be achieved by gradual decrease of the field down to zero after initial transformation of MnSi to a spin-polarized state in high fields $H$. This can be achieved only for $\bf{H}\parallel$ [111]. Investigations of MnSi in magnetic SDS give us a possibility to determine the two components of low field magnetic susceptibility of this compound, $χ_{\perp}(T)$ and $χ_{\parallel}(T)$ [$χ_{\perp}$ and $χ_{\parallel}$ correspond to $\bf{H}\perp$, and $\bf{H}\parallel$ (111)-plane containing magnetic moments in helically ordered state]. These results are compared with macroscopic magnetic susceptibility of MnSi earlier determined for this compound only in magnetic multi domain state (MDS). In addition our results are compared with the data reported for some non-monochiral helimagnets. Characteristic features of monochiral helimagnets are elucidated.
Comparative study of helimagnets MnSi and Cu2OSeO3 at high pressures
本文用交流量热法研究了高压下螺旋磁体Cu_2OSeO_3和MnSi的热容。尽管它们的磁矩性质不同,但Cu2OSeO3和MnSi在相变时的磁性和热力学性质的行为表现出惊人的相似性。如果作为温度的函数进行分析,则两种物质(峰和肩)在相变时的热容的两个特征在高压下也以类似的方式表现。这可能意味着像MnSi这样的弱巡回磁体的典型纵向自旋波动对相变的贡献很小。热容量曲线的肩部随着温度的降低而收缩,这表明它们来自经典涨落。在MnSi的情况下,尖锐的峰和肩部的热容同时消失,可能意味着存在一个三临界点,并确认在MnSi以及在Cu 2 OSe O 3的一级相变的波动性质。
Magnetic structure of the MnGe helimagnet and representation analysis
在最近的结果为原型helimagnet MnSi,我们研究了可能的磁性结构的化合物的同一家庭,一致的晶体对称性时,磁传播矢量平行于[001]轴。对MnGe中记录的已发表的μ子自旋旋转谱的分析[Phys. Rev. B 93,174405(2016)]显示,与MnSi不同,没有偏离正则螺旋结构。这种质的差异要求进一步的理论工作手征磁体。
Direct observations of spin fluctuations in spin-hedgehog-anti-hedgehog lattice states in MnSi$_{1-x}$Ge$_x$ ($x=0.6$ and $0.8$) at zero magnetic field
本研究利用 TOF 中子非弹性散射和 MIEZE 自旋回波技术观测 MnSi$_{1-x}$Ge$_x$ 的 SHAH 晶格态自旋涨落,揭示其与正霍尔电阻率温度区间的对应,支持符号偏置标量自旋手性机制。
History dependence of the magnetic properties of single-crystal Fe$_{1-x}$Co$_{x}$Si
本文报道了Fe $_{1-x}$ Co $_{x}$ Si,$0.20 \leq x \leq 0.50$光学浮区单晶的磁化强度、交流磁化率和比热。我们确定所有主要的结晶方向和冷却历史的磁相图。零场冷却后,相图类似于原型的化学计量立方手性磁铁锰硅。除了螺旋和锥形状态,我们观察到一个口袋的skyrmion晶格相低于helimagnetic有序温度。在这些国家之间的相边界的证据缓慢动态观察。当样品在小磁场中冷却时,Skyrmion晶格的相袋可以亚稳地持续到最低温度。结合转变温度、转变场和螺旋波长随组成的变化,这种滞后确定Fe $_{1-x}$ Co $_{x}$ Si是未来实验探索的理想材料,例如,Skyrmion晶格的拓扑解旋。