受到晶界和表面对电子散射的影响,金属纳米薄膜在导电和导热方面表现出与体材料不同的性质。实验研究了厚度为76nm的金薄膜在不同温度(3-240K)下的导电和导热特性。结果表明薄膜电导率和热导率均大大低于体材料值;薄膜和体材料的电导率随温度变化趋势相同,热导率的变化趋势相反;薄膜的Lorenz数大于体材料值,Wiedemann-Franz定理不成立。
Due to surface and grain boundary scattering, thermal and electrical properties of gold nanofihns exhibit significant difference compared with bulk value. Gold nanofilms with thickness of 76 nm were studied in temperature range of 3-240 K. Experimental results indicate that the electrical and thermal conductivity of gold nanofilms are greatly reduced compared to the bulk value. It diflhrent from bulk to thermal conductivity while is consistent to electrical conductivity with temperature change. Lorenz number of gold nanofilms is higher than the corresponding bulk value, which indicates Wiedemann-Franz law is inapplicable in gold nanofilms.