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以硼砂、铝粉、氯化铵为原料,利用高压水热法合成了长度为2~5μm,直径为45~110 nm,长径比可达225的硼酸铝纳米晶须。采用X-射线衍射(XRD)、超高分辨场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、X射线能谱(EDS)对合成产物进行了表征。结果表明,在高压下,氯化铵分解生成的氨气阻碍了氧化硼颗粒过于团聚在氧化铝颗粒周围,避免了侧面上过饱和度增高,从而抑制了径向生长的二维成核,晶须在生长过程中,表面上吸附的有限氧化硼通过表面扩散向结晶尖端迁移,给晶须尖端上的螺旋位错供料。
Borax, aluminum powder and ammonium chloride were used as raw materials to synthesize aluminum borate nanowhiskers with length of 2 ~ 5μm, diameter of 45 ~ 110 nm and aspect ratio of 225 by hydrothermal method. The synthesized products were characterized by XRD, FESEM, TEM and EDS. The results show that under high pressure, ammonia gas formed by the decomposition of ammonium chloride hinders the boron oxide particles from being agglomerated around the alumina particles and avoids the increase of supersaturation on the side surface, thereby inhibiting the radial growth of two-dimensional nucleation and crystallization During the growth process, the limited boron oxide adsorbed on the surface migrates to the crystal tip through surface diffusion, feeding the screw dislocations on the tip of the whisker.