Electric and thermal conduction mechanisms of submicron-structured Ni-ZrO_2 composites  

作　　者：范秋林 胡行方 郭景坤 

机构地区：[1]Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China

出　　处：《Science China Mathematics》1995年第11期1377-1386,共10页中国科学：数学（英文版）

基　　金：the State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China

摘　　要：The experimental results indicate that the Ni-ZrO2 composites synthesized with urn-sized Ni powder and nm-sized ZrO2 powder possess submicron structure. Based on the fractal theory, the relationship between the electric and thermal conductance and the chemical composition of the composites has been studied. The results show that with the increase of the nickel content, the electric and thermal conductance of the composites varies. It is proposed that in the submicron structured composites, electrons and phonons have different transport mechanisms. The electric transport in the submicron-structured composites can be attributed to the medium punch-through effect and quantum tunnel punch-through effect of electrons and the low thermal conductance is due to the phonic scattering by the submicron-sized pores, grains and grain boundaries. The reason can also be used to explain why the thermal percolation threshold value lags behind the electric percolation value. The phenomenon has been observed.The experimental results indicate that the Ni-ZrO2 composites synthesized with urn-sized Ni powder and nm-sized ZrO2 powder possess submicron structure. Based on the fractal theory, the relationship between the electric and thermal conductance and the chemical composition of the composites has been studied. The results show that with the increase of the nickel content, the electric and thermal conductance of the composites varies. It is proposed that in the submicron structured composites, electrons and phonons have different transport mechanisms. The electric transport in the submicron-structured composites can be attributed to the medium punch-through effect and quantum tunnel punch-through effect of electrons and the low thermal conductance is due to the phonic scattering by the submicron-sized pores, grains and grain boundaries. The reason can also be used to explain why the thermal percolation threshold value lags behind the electric percolation value. The phenomenon has been observed.

关 键 词：SUBMICRON structure electronic PUNCH-THROUGH effect phonic scattering ABNORMAL resonance. 

分 类 号：TB331[一般工业技术—材料科学与工程]