摘要
The local thermal conductivity of polycrystalline aluminum nitride (A1N) ceramics is measured and imaged by using a scanning thermal microscope (SThM) and complementary scanning electron microscope (SEM) based techniques at room temperature. The quantitative thermal conductivity for the A1N sample is gained by using a SThM with a spatial resolution of sub-micrometer scale through using the 3w method. A thermal conductivity of 308 W/m-K within grains corresponding to that of high-purity single crystal A1N is obtained. The slight differences in thermal conduction between the adjacent grains are found to result from crystallographic misorientations, as demonstrated in the electron backscattered diffraction. A much lower thermal conductivity at the grain boundary is due to impurities and defects enriched in these sites, as indicated by energy dispersive X-ray spectroscopy.
The local thermal conductivity of polycrystalline aluminum nitride (A1N) ceramics is measured and imaged by using a scanning thermal microscope (SThM) and complementary scanning electron microscope (SEM) based techniques at room temperature. The quantitative thermal conductivity for the A1N sample is gained by using a SThM with a spatial resolution of sub-micrometer scale through using the 3w method. A thermal conductivity of 308 W/m-K within grains corresponding to that of high-purity single crystal A1N is obtained. The slight differences in thermal conduction between the adjacent grains are found to result from crystallographic misorientations, as demonstrated in the electron backscattered diffraction. A much lower thermal conductivity at the grain boundary is due to impurities and defects enriched in these sites, as indicated by energy dispersive X-ray spectroscopy.
作者
张跃飞
王丽
R.Heiderhoff
A.K.Geinzer
卫斌
吉元
韩晓东
L.J.Balk
张泽
Zhang Yue-Fei;Wang Li;R.Heiderhoff;A.K.Geinzer;Wei Bin;Ji Yuan;Han Xiao-Dong;L.J.Balk;Zhang Ze(Institute of Microstructure and Property of Advanced Materials,Beijing University of Technology,Beijing 100124,China;Department of Electronics,Faculty of Electrical,Information and Media Engineering,University of Wuppertal,Wuppertal D-42119,Germany;Department of Materials Science,Zhejiang University,Hangzhou 300038,China)
基金
Project supported by the National Basic Research Program of China(Grant No.2009CB623702)
the National Natural Science Foundation of China(Grant No.10904001)
the Key Project Funding Scheme of Beijing Municipal Education Committee,China(Grant No.KZ201010005002)