非共线反铁磁Weyl半金属Mn_(3)Ge中电磁特性的质量依赖

Quality Dependence of Electromagnetic Properties of Non-Collinear Antiferromagnetic Weyl Semimetal Mn_(3)Ge

近年来的一些实验和理论研究证实,Mn3X系列材料具有非共线反铁磁Weyl半金属的特征,有很大的应用潜力,其中以Mn3Sn和Mn_(3)Ge最为突出。使用助熔剂法制备得到了两块Mn_(3)Ge的晶体,对其电输运和磁特性进行了详细研究。结果表明,晶体的电磁特性与其质量有很强的依赖关系。过量的Mn占据Ge原子的位点会导致材料内部缺陷增多,在Mn与Ge的原子数分数之比为76.88∶23.12时,晶体的交换偏置场强度在温度T=2 K以及5×10^(4)Oe(1 A·m-1=4π×10^(-3)Oe)场冷却的条件下增强了47%,反常霍尔电导率在T=100 K时高场(±3×10^(4)Oe)的饱和值提升了1.7倍。并且对现象背后的物理机理进行了探讨。该研究表明,电输运和磁特性的质量依赖可以提供与以往电、磁等调节性能方式不同的手段,对开关和存储器件的开发具有一定的参考价值。

In recent years,some experimental and theoretical studies have confirmed that Mn3X series materials have the characteristics of non-collinear antiferromagnetic Weyl semi-metal and have great application potential.Among them,Mn3Sn and Mn_(3)Ge are the most prominent.Two Mn_(3)Ge crystals were prepared by flux method,and their electrical transport and magnetic properties were studied in detail.The results show that the electromagnetic properties of the crystals are strongly dependent on their qualities.Excessive Mn occupying the sites of Ge atoms can lead to the increase of internal defects in the materials.When the atomic number fraction ratio of Mn to Ge is 76.88∶23.12,the exchange bias field intensity of the crystal increases by 47%under the condition of T=2 K and 5×10^(4)Oe(1 A·m-1=4π×10^(-3)Oe)field cooling.The saturation value of the abnormal Hall conductivity in high magnetic field with field strength of±3×10^(4)Oe increases by 1.7 times at T=100 K.The physical mechanism behind the phenomenon was discussed.The research shows that the quality dependence of electrical transport and magnetic characteristics can provide different means to adjust the performances from the previous methods such as electricity and magnetism,which has certain reference value for the development of switches and memory devices.