采用脉冲激光沉积技术制备了钴纳米薄膜,分析和讨论了不同背景气压和脉冲频率对钴纳米薄膜表面形貌的影响及纳米微粒的形成机理.实验结果表明:在低背景气压下,等离子体羽辉自身粒子之间的碰撞占主导作用,容易形成液滴;在较高背景气压下,等离子体羽辉边缘粒子和背景气体粒子之间的碰撞占主导作用,容易形成小岛并凝聚成微颗粒;在4Hz的脉冲重复频率和5Pa背景气压下生长出单分散性良好的钴纳米颗粒.

This paper describes the fabrication of cobalt nano-thin films by pulsed laser ablation of cobalt target in a hydrogen background gas.KrF laser and x-y laser scanning apparatus is used,and cobalt target is rotated at a rate of 20Hz.The deposition environment and its effect on thin film surface morphology are analyzed,and mechanism of forming particles is discussed.The results show that under lower background gas pressure it inclines to form droplet because the collision among plasmas themselves is prominent.While isles and then form particles agglomerate under higher background gas pressure.Monodispersed cobalt nanoparticles grow at a repetition rare of 4Hz and 5Pa background gas.