毫微晶Pd的热电势率  

THE THERMOELECTRIC POWER OF NANOCRYSTALLING Pd

作　　者：崔平[1] 阮耀钟[2] 王瑞平[2] 黄大金[2] 

机构地区：[1]中国科学院固体研究所,合肥230031 [2]中国科学技术大学物理系,合肥230026

出　　处：《低温物理学报》1991年第2期107-109,共3页Low Temperature Physical Letters

摘　　要：测量了晶粒尺寸为6.6～23nm 的亳微晶 Pd 从77K 到273K 的热电势率.结果表明,毫微晶 Pd 的热电势率强烈地依赖于晶粒尺寸.我们认为这可能是由于过渡金属 Pd 的电子能带结构或费米能随晶粒尺寸变化所致.High vacuum evaporation condensation method was utilized to generate nanocrystalline Pd with a crystal size ranging from 6.6 nm to 23 nm.The nano-sized Pd was pressed into disk-like pellets and the thermoelectric power (TEP) was measured by the differential method.The behavior of TEP between 77 K and 273 K has been determined.The result shows that the TEP of nanocrystalline Pd depends on the grain size strongly.The temperature dependence ofthe TEP is diferent from that of conventional polycrystalline Pd----the TEP keeps positivebetween 77 K and 273 K when the grain size is smaller than 10 nm.A qualitative interpretation for these new phenomena is prpoposed.Due to the large number (~1019cm-3) of interfaces of different atomic structures in this kind of new material the interfacial component exhibits a little short-range order and,thus,differs from the two known solid band structure and/or Fermi energy of nanocrystals may be associated with their grain size As a consequence,the TEP of nanocrystalline Pd may be controlled by their microstructural parameter such as grain size,according to the Mott model.

关 键 词：毫微晶P∨d 热电势率 温度 微分法 

分 类 号：O753.1[理学—晶体学]