离子注镧对镍氧化膜生长及其膜内应力的影响

Influence of La ion-implantation on growth and stress status of oxide film formed on nickel

对纯镍及其表面离子注镧样品在900℃空气中的恒温氧化规律进行研究.用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对NiO膜的微观形貌和结构进行测试.用激光拉曼(Raman)光谱仪和X射线衍射仪(XRD)对2种样品表面氧化膜的应力状态进行测量.用次级离子质谱仪(SIMS)对氧化膜内元素Ni、O和La的深度分布情况进行测量.结果表明:离子注镧显著降低了镍的恒温氧化速率,细化了表面NiO膜的晶粒尺寸;同时将氧化膜的生长由注镧前Ni2+阳离子的向外扩散转变为注镧后O2-阴离子的向内扩散为主.X射线衍射和激光拉曼光谱测量均反映出注镧引起的膜内应力降低效应,并且结合氧化膜内应力深度分布的不均匀性及膜生长过程中存在的稀土元素效应,对2种应力测量结果之间存在的偏差进行了细致分析.

Isothermal oxidation behavior of pure nickel and its lanthanum ion-implanted sample is studied at 900 ℃ in air.The surface morphology and microstructure of NiO films formed on both samples are examined by scanning electronic microscopy（SEM） and transmission electronic microscopy（TEM）.Laser Raman spectrometer and X-ray diffraction spectrometer（XRD） are used to study the stress status of NiO films formed on La-free and La-implanted nickel.Secondary ion massive spectrum（SIMS） is used to examine Ni,O and La element depth distribution in oxide films.Results show that La-implantation remarkably reduces the growing speed and grain size of NiO film.Meanwhile it changes the oxide film growing mechanism from predominant Ni2＋ cation outward diffusion to O2-anion inward diffusion.XRD and Raman testing results show the stress declination effect due to La-implantation,while the discrepancy between the two testing results is fully analyzed regarding to the heterogeneous stress distribution in oxide film and the rare earth effect during the film growing process.