A1N陶瓷中的晶格缺陷

LATTICE DEFECTS IN AIN CERAMICS

用透射电镜观察了不同热导率的Ａ１Ｎ陶瓷中存在的晶格缺陷，这类缺陷主要以位错线形式呈现，分布不均匀，大多集中在晶界处。一些晶粒中存在反相畴界。热导率不同的试样其缺陷密度明显不同，氧杂质进入Ａ１Ｎ晶格并形成铝空位是产生晶格缺陷的主要原因，也对晶格参数有显著影响。分析了抑制晶格缺陷形成、提高热导率的工艺措施。

The lattice defects in AIN ceramic specimens with different thermal conductivities were observed by TEM. The lattice defects appear mainly in the form of dislocation lines, which are distributed unequally and mostly concentrated at the grain boundaries. Antiphase domain boundary also exists in some grains. The defect density for AIN samples with different thermal conductivities are obviously different. It is considered that the dissolution of oxygen impurities into AIN lattice leading to form aluminum vacancies is the most important factor in producing lattice defects, which may also affect the latttice parameters. The process for prohibiting the formation of lattice defectS and increasins the thermal conductivity is discussed.