摘要
用 AES 原位加热的方法研究了 Ni_(84)P_(16)非晶合金中磷原子的表面偏析现象。在实验温度范围内,磷向自由表面的偏析是由体扩散控制的,表面浓度 C_S 随退火时间 t 的变化符合 Hoffmann—Erlewein关系(H—E关系)。在250—350℃温区内,磷原子单独向表面偏析,扩散系数 D 位于1.1×10^(-24)—9.0×10^(-22)m^2s^(-1)之间,D 与 T 符合 Arrhenius 关系,其中指数前因子 D_0=2.81×10^(-6)m^2s~_(-1),扩散激活能E_0=1.70eV。在380℃退火时,晶化产生的晶界加速 P 偏析,同时促进 Ni 向自由表面扩散。
The surface segregation of phosphorous in Ni_(84)P_(16)amorphous alloy has beeninvestigated by means of AES with heating in situ.Within the experimental temperatures,thesurface segregation of P was controlled by bulk diffusion,surface concentrations varied with theannealing time are in good agreement with H-E equation.From 250 to 350℃,P segregated tothe surface alone,the diffusion coefficients lie between 1.1x10^(-24)and 9.0x10^(-22)m^2s^(-1),andArrhenius relationship is established,whereas the preexpotential factor D_0=2.81x10^(-6)m^2s^(-1),activation energy E_D=1.70eV.Annealing at 380℃,the grain boundaries which were yieldedfrom crystallization could accelerate P segregation,simultaneously,Ni was promoted to segre-gate towards surface by the rapid P diffusion.
关键词
表面偏析
原子扩散
磷
合金
镍
surface segregation
atomic diffusion
AES
