论文标题
抗位点障碍和浆果曲率驱动的异常大厅效应在无间隙的半导体MN2Coal Heusler化合物中
Anti-site disorder and Berry curvature driven anomalous Hall effect in spin gapless semiconducting Mn2CoAl Heusler compound
论文作者
论文摘要
无自旋间隙的半导体具有一个自旋通道的有限带隙和另一个自旋通道的封闭缝隙,成为一种新的磁性材料状态,具有巨大的自旋应用潜力。在抗反效力的MN2COAL中观察到无自旋间隔半导体行为的第一个实验证据。在这里,我们使用实验和理论研究报告了MN2Coal中晶体结构和异常霍尔效应的详细研究。对高分辨率同步加速器X射线衍射数据的分析显示了反赫斯勒逆结构内Mn和Al原子之间的抗位于疾病。依赖温度的电阻率显示出半导体的行为,并遵循Mooijs金属无序的标准。异常大厅电阻率的缩放行为表明,MN2Coal中的异常霍尔效应主要受动量空间中浆果曲率引起的内在机制的控制。发现实验性的固有霍尔电导率(AHC)为35 s/cm,比有序的MN2Coal的理论上预测值大得多。我们的第一原则计算得出的结论是,Mn和Al Atoms之间的抗部位疾病增强了浆果曲率,因此与实验非常吻合,因此内在AHC的价值非常吻合。
Spin gapless semiconductors exhibit a finite band gap for one spin channel and closed gap for other spin channel, emerged as a new state of magnetic materials with a great potential for spintronic applications. The first experimental evidence for the spin gapless semiconducting behavior was observed in an inverse Heusler compound Mn2CoAl. Here, we report a detailed investigation of the crystal structure and anomalous Hall effect in the Mn2CoAl using experimental and theoretical studies. The analysis of the high-resolution synchrotron x-ray diffraction data shows anti-site disorder between Mn and Al atoms within the inverse Heusler structure. The temperature-dependent resistivity shows semiconducting behavior and follows Mooijs criteria for disordered metal. Scaling behavior of the anomalous Hall resistivity suggests that the anomalous Hall effect in the Mn2CoAl is primarily governed by intrinsic mechanism due to the Berry curvature in momentum space. The experimental intrinsic anomalous Hall conductivity (AHC) is found to be 35 S/cm, which is considerably larger than the theoretically predicted value for ordered Mn2CoAl. Our first-principle calculations conclude that the anti-site disorder between Mn and Al atoms enhances the Berry curvature and hence the value of intrinsic AHC, which is in a very well agreement with the experiment.