层状结构富Mg的Mg_(2)Sn薄膜相组成与热电性能  

Phase Composition and Thermoelectric Properties of the Layered Mg_(2)Sn Thin Films Rich Mg

作　　者：刘莹[1] 宋贵宏[1] 李贵鹏 陈雨 胡方[1] Liu Ying;Song Guihong;Li Guipeng;Chen Yu;Hu Fang(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《稀有金属材料与工程》2022年第5期1780-1788,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51772193)。

摘　　要：利用高真空磁控溅射设备,通过顺序沉积制备富Mg的Mg_(2)Sn热电薄膜。使用X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及能谱仪(EDS)研究了沉积薄膜的物相组成、表面和截面形貌、元素含量及分布。使用塞贝克(Seebeck)系数/电阻分析系统LSR-3测量了沉积薄膜的电阻率和Seebeck系数,进而研究不同Mg含量的Mg_(2)Sn薄膜的功率因子。结果表明,采用磁控溅射法可以制备出立方反萤石结构的Mg_(2)Sn相薄膜,XRD显示,沉积薄膜是由立方结构的Mg_(2)Sn相和少量的纳米尺寸的金属Mg相组成。随着Mg靶溅射时间的增加,纳米金属Mg相的含量增加,电阻率和Seebeck系数均表现为先升高后降低,这归因于少量纳米金属Mg相与基体相之间存在相界面。适量的金属Mg相存在于Mg_(2)Sn薄膜中,有利于提高Seebeck系数。含有适量纳米尺寸金属Mg相的Mg_(2)Sn沉积膜,因其Seebeck系数较高,电阻率适当,可获得较高的功率因子。层状结构的Mg_(2)Sn薄膜可显著提高Seebeck系数,尽管电阻率也增加,但最终使薄膜的功率因子显著提高。The Mg_(2)Sn thermoelectric films with a tiny metal Mg phase were prepared using a Mg-Sn alloy and a high pure metal Mg target by magnetron sputtering alternately.The phase composition,surface and cross-sectional morphology,element content and distribution of the deposited films were studied by X-ray diffraction(XRD)pattern,scanning electron microscope(SEM),and energy diffraction spectrometer(EDS).The resistivity and Seebeck coefficients of the deposited films were measured by the Seebeck coefficient/resistance analysis system LSR-3.And the power factor of the Mg_(2)Sn film with different Mg contents was studied.The XRD shows that the deposited film is composed of nano-sized Mg_(2)Sn phase with cubic anti-fluorite structure and a small number of nano-sized metal Mg phase.The content of nano-sized metallic Mg phase increases with increasing Mg target sputtering time,and the resistivity and Seebeck coefficient increase first and then decrease,which is due to the phase interface between the nano-sized metallic Mg phases and substrate phases.The nano-sized metal Mg phase with proper quantity exists in the Mg_(2)Sn film,which is beneficial to improve the Seebeck coefficient.The deposited Mg_(2)Sn films containing proper quantity of nano-sized metallic Mg phase possess a higher power factor due to their high Seebeck coefficient and appropriate resistivity.The layered Mg_(2)Sn film can significantly increase the Seebeck coefficient and the power factor of the film is significantly improved even if the resistivity increases.

关 键 词：热电材料 Mg_(2)Sn薄膜 SEEBECK系数 层状结构 电阻率 

分 类 号：TB34[一般工业技术—材料科学与工程]