(上海交通大学 国家教育部高温材料与测试开放实验室,上海 200030)
摘 要: 采用电刷镀工艺制备了厚度<1μm的钯膜。AFM和SEM观测表明钯膜由半球型的纳米晶簇构成,晶簇尺寸在20~30 nm之间;在薄膜中没有发现裂纹和气孔。利用电化学剥离方法测定了氢在α薄膜的扩散系数(298~328 K)。氢的扩散行为符合Arrhenius定律。扩散系数比相同温度下体材料的扩散系数低1个数量级,表明晶界阻碍了氢的扩散。
关键字: 钯; 氢; 纳米晶; 扩散
(Key Lab of the Ministry of Education for High Temperature Materials & Testing,
Shanghai Jiaotong University, Shanghai 200030, P.R.China)
Abstract:Thin (less that 1μm) and continuous palladium film was fabricated by brush plating. The topography and cross-sections of the film were characterized by atom force microscopy (AFM) and scanning electron microscopy (SEM). The results showed that there are no cracks and pinholes in the film. The film is made up of spherical nano-clusters. The size of most clusters is 20~30nm. The hydrogen coefficient, DH , in the Pd film was measured by electrochemical stripping method in the Pd-H solid solution (α-phase) at the temperature ranging from 298 to 328K. The DH is 1 order of magnitude smaller than that in the bulk. An equation is given to calculate the total charge due to hydrogen diffusion. The DH vs 1/T plots show that the film follows Arrhenius behavior, DH=D0 exp(- Ea/RT), with a activation energy larger than that in bulk Pd. The diffusion of hydrogen was suffered by the crystal interface.
Key words: palladium; hydrogen; diffusion; nano-crystal