碘嵌入Cr$_2$Se$_3$中的磁耦合电荷输运交叉与巨负磁电阻
Magnetically coupled charge-transport crossover and giant negative magnetoresistance in iodine-incorporated Cr$_2$Se$_3$
- Indian Association for the Cultivation of Science（印度科学文化研究所）
- Lomare Technologies Limited（Lomare科技有限公司）
- Indian Institute of Technology Tirupati（蒂鲁帕蒂印度理工学院）
- Brno University of Technology（布尔诺理工大学）
- UGC-DAE Consortium for Scientific Research（UGC-DAE科学研究联盟）
- Bose Institute（博斯研究所）
- Central European Institute of Technology（中欧技术研究所）
- Sincrotrone Trieste s.c.p.a.（的里雅斯特同步辐射中心）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过实验与理论结合，发现碘嵌入Cr$_2$Se$_3$在高温下出现磁耦合输运交叉及巨负磁电阻，为调控非层状过渡金属硫族化合物的电子与磁性质提供了新途径。
AI中文摘要：
我们报道了通过结构、磁性、输运、光谱及第一性原理方法对碘嵌入Cr$_2$Se$_3$（一种非范德瓦尔斯准二维磁性材料）的合成与全面研究。磁化强度和电子自旋共振测量揭示了在$T_N \approx 52$ K以下存在反铁磁有序态。在更高温度下，在$T^* \approx 150$ K附近出现第二个更宽的异常，与温度依赖电阻率中的浅极小值相吻合，类似于金属-绝缘体交叉。霍尔测量表明，在高温（≥150 K）下以空穴型导电为主，而$T^*$以下的非线性霍尔响应以及三次谐波电信号的异常，暗示了依赖于迁移率的多通道和空间不均匀输运的出现。在25 K和12 T下，大的非饱和负磁电阻达到约-78%，进一步证明了电荷输运与磁态之间的强耦合。温度依赖拉曼光谱显示在$T^*$附近没有对称性变化的结构相变，而角分辨光电子能谱（ARPES）测量显示，在交叉过程中占据电子结构没有重大重构。综合来看，这些结果将高温异常确定为一种宽泛的磁耦合输运交叉，源于短程磁关联、化学无序和竞争导电通道间重新分布的相互作用。这些发现表明，阴离子嵌入为调控非层状Cr$_2$Se$_3$的耦合电子和磁性质提供了有效途径，将该系统确立为研究过渡金属硫族化合物中关联输运和新兴自旋电子学功能的有前景平台。
英文摘要：
We report the synthesis and comprehensive investigation of iodine-incorporated $Cr_2Se_3$, a non-van der Waals quasi-two-dimensional magnetic material, using structural, magnetic, transport, spectroscopic, and first-principles methods. Magnetization and electron spin resonance measurements reveal an antiferromagnetically ordered state below $T_N \approx 52$ K. At higher temperatures, a second, broader anomaly emerges near $T^* \approx 150$ K, coinciding with a shallow minimum in the temperature-dependent resistivity that resembles a metal-to-insulator-like crossover. Hall measurements indicate predominantly hole-like conduction at high temperatures ($\geq$ 150 K), while the nonlinear Hall response below T*, together with an anomaly in the third-harmonic electrical signal, suggests the emergence of mobility-dependent multichannel and spatially inhomogeneous transport. A large, non-saturating negative magnetoresistance reaching approximately -78\% at 25 K and 12 T further demonstrates strong coupling between charge transport and the magnetic state. Temperature-dependent Raman spectroscopy reveals no symmetry-changing structural transition near T*, whereas angle resolved photoemission spectroscopy (ARPES) measurements show no major reconstruction of the electronic structure occupied across the crossover. Taken together, these results identify the high-temperature anomaly as a broad magnetically coupled transport crossover arising from the interplay of short-range magnetic correlations, chemical disorder, and redistribution among competing conduction channels. These findings demonstrate that anion incorporation provides an effective route to tuning the coupled electronic and magnetic properties of non-layered Cr$_2$Se$_3$, establishing this system as a promising platform for investigating correlated transport and emergent spintronic functionalities in transition-metal chalcogenides.
