ZrCuSiAs型锰基化合物ThMnSbN中的化学压力效应  

Chemical pressure effects in ZrCuSiAs-type manganese-based compound ThMnSbN

作　　者：肖宇森 段清晨 李佰卓 柳绍华 祝钦清 谭树刚 景强 任之 梅玉雪 王操 曹光旱[2] Xiao Yu-Sen;Duan Qing-Chen;Li Bai-Zhuo;Liu Shao-Hua;Zhu Qin-Qing;Tan Shu-Gang;Jing Qiang;Ren Zhi;Mei Yu-Xue;Wang Cao;Cao Guang-Han(Shool of Physics and Optoelectronics,Shandong University of Technology,Zibo 255000,China;Department of Physics,Zhejiang University,Hangzhou 310027,China;School of Science,Westlake University,Hangzhou 310024,China)

机构地区：[1]山东理工大学物理与光电工程学院,淄博255000 [2]浙江大学物理系,杭州310027 [3]西湖大学理学院,杭州310024

出　　处：《物理学报》2022年第4期186-194,共9页Acta Physica Sinica

基　　金：国家重点研究发展计划(批准号:2017YFA0303002);山东省自然科学基金(批准号:ZR2019MA036,ZR2016AQ08)资助的课题。

摘　　要：采用固相反应法合成了一种ZrCuSiAs型准二维层状锰基化合物ThMnSbN.基于X射线粉末衍射的结构精修显示,该化合物属于P4/nmm空间群.其晶胞参数为a=4.1731Å,c=9.5160Å.电输运测量显示,该化合物电阻率随温度下降缓慢上升,且在16 K附近出现电阻率异常.与此同时,该材料的磁化率在同一温度附近出现异常,显示出类似磁性相变的行为.进一步的比热测量中没有观察到磁相变导致的比热异常.另外,低温下的比热分析显示,该材料的电子比热系数为γ=19.7 mJ·mol^(-1)·K^(-2),远高于其他同类锰基化合物.该结果与电输运测量中观察到的低电阻率行为相符,暗示ThMnSbN中费米面附近存在可观的电子态密度.基于对一系列ZrCuSiAs型化合物晶体结构细节的比较,分析了含有萤石型Th_(2)N_(2)层的系列化合物中导电层所受化学压力的不同作用形式.A quasi-two-dimensional manganese-based compound ThMnSbN is synthesized by the solid-state reaction method.Structural refinement based on X-ray powder diffraction shows that the compound structure belongs to the P4/nmm space group.The lattice parameters are a=4.1731Åand c=9.5160Å.Electrical transport measurements show that the resistivity of the compound is the lowest in the Mn-based family.When cooling it,its resistivity rises slowly and shows a shoulder-like anomaly at 16 K.Also,the magnetic susceptibility exhibits an anomaly at the very same temperature.Though the specific heat data indicate the inexistence of transition-induced anomaly,the electron specific heat coefficient ofγ=19.7 mJ·mol^(-1)·K^(-2) is derived by fitting the low-temperature C-T curve.Thisγvalue is much higher than those of the isostructural manganese-based compounds.Thus,the specific heat is consistent with the low resistivity,implying a considerable electronic density of states near the Fermi surface for ThMnSbN.By comparing the crystal structure for a group of ZrCuSiAs-type compounds,various chemical pressure effects of the fluorite-type Th_(2)N_(2) layer on the conducting layer in different compounds are discussed.

关 键 词：锰基化合物 晶体结构 物性测量 化学压力效应 

分 类 号：TB34[一般工业技术—材料科学与工程]