Many interesting physical phenomena emerge in the vicinity of phase transition temperature (T_c) for magnetic materials. However, it remains a big challenge to elucidate the near-T_c behaviors of chiral helimagnets, owing to their diversified magnetic interactions and complicated phase transitions. Here, we have systematically studied the near-T_c properties of a chiral helimagnet Cr_1/3NbS₂ by magnetotransport measurements with fine tuning of temperature and magnetic field. An anomalous positive magnetoresistance (MR) appears around the critical field (H_c) in a narrow temperature range (~ 128–132 K), which can be attributed to the competing scattering effects on electrons between the chiral magnetic order and thermal fluctuation near critical point. Moreover, the negative MR continues to increase even above H_c, and this behavior becomes more pronounced near T_c. Based on the MR results, a near-T_c magnetic phase diagram of Cr_1/3NbS₂ is presented, with a particular emphasis on the determination of internal phase boundary of chiral soliton lattice (CSL). This work gains an insight on the near-T_c behaviors of chiral magnetic materials and sheds light on the related electronic and spintronic applications.

许多有趣的物理现象出现在相转变温度（的附近Ť _Ç用于磁材料）。然而，由于其多样化的磁相互作用和复杂的相变，阐明手性螺旋磁体的近T _c行为仍然是一个巨大的挑战。在这里，我们通过对温度和磁场进行微调的磁传输测量系统地研究了手性螺旋磁体 Cr _1/3 NbS ₂的近T _c特性。临界场周围出现异常正磁阻 (MR) ( H _c) 在较窄的温​​度范围内 (~ 128–132 K)，这可归因于手性磁序和临界点附近的热波动之间对电子的竞争性散射效应。此外，负 MR 甚至在高于H _{c 时}继续增加，并且这种行为在T _c附近变得更加明显。基于MR结果，给出了Cr _1/3 NbS ₂的近T _c磁相图，特别强调了手征孤子晶格（CSL）内相边界的确定。这项工作深入了解了近T _c 手性磁性材料的行为，并阐明相关的电子和自旋电子应用。