高温高压下立方氮化硼晶体的生长机制  

Growth Mechanism on cBN Crystals under High Pressure and High Temperature

作　　者：周艳平[1] 闫学伟[1] 马贤峰[1] 赵廷河 

机构地区：[1]中国科学院长春应用化学研究所

出　　处：《无机材料学报》1995年第4期391-398,共8页Journal of Inorganic Materials

基　　金：国家自然科学基金

摘　　要：在４．５～５．０ＧＰａ，１５００～１８００℃范围内，对在Ｌｉ基复合氮化物或氮硼化物的催化体系中以及其中添加Ｌｉ８ＳｉＮ４后合成ｃＢＮ进行了研究，探讨了ｃＢＮ晶体的表面构造和生长机制，研究了由六方氨化硼向立方氮化硼转变过程中硅的存在行为．本实验中合成的立方氮化硼为具有光泽的棕色透明单晶．Cubic boron nitride was synthesized under the conditions of the high pressure of 4.5～5.0GPa and the high temperature of 1500～1800℃. We compared with the two types of cBN synthesised in the Licomplex nitrides or boride nitrides catalytic system and in the catalytic system above contained additive complex nitride Li8SiN4. The surface structure and growth mechanism of cBN crystal were approached.On the basis of the holes, pits and a flight of steps as well as helixes of grown steps on the surface of cBN crystal, we confirm that nucleuses formed by defects and growth controled with dislocation are a general characteristic of cBN growth. The effect behavior of silicon in the phase transformatinn from hBN to cBN was studied. When complex nitride Li8SiN4 is added into the catalytic system, its partial dissolution increases saturation degree and viscosity Of melt which increase crystal boundary energy and reduce nucleation velocity. The glossy transparent cBN crystals in brown were synthesized.

关 键 词：高温 高压 氮化硼 晶体生长 立方氮化硼 

分 类 号：O781[理学—晶体学] O613.81