Ningkang Huang

Microanalyses of Ar+-bombarded zirconia-yttria films on silicon substrates

Abstract Zirconia-yttria films containing 8.0 wt.% Y2O3 were prepared on silicon substrates by r.f. magnetron sputter deposition followed by 170 keV Ar+ ion bombardment at room temperature. The microanalyses of ion-bombarded zirconia-yttria films with different ion doses have been carried out by X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy. It was found that the amorphous films deposited with r.f. magnetron sputtering were partly crystallized after Ar+ ion bombardment, and that amount of crystallization was dependent on the dose of ion bombardment. The oxidized states of Zr 3d and Y 3d XPS peaks were observed under argon ion bombardment of different doses.

XPS investigation of niobium implanted into sapphire after annealing in reducing atmosphere

Abstract X-ray photoelectron spectroscopy (XPS) has been used to determine the depth profile and chemical states of the implanted niobium in (0 1 1 2) sapphire after annealing with a series of steps from 500∘C to 1100∘C in a reducing atmosphere. It is found that such an annealing procedure for the 380 keV niobium with a dose of 5×1016 ions/cm2 implanted into (0 1 1 2) sapphire at room temperature causes Nb migration towards the surface and results in a two-peak feature distribution profile with the large peak at the surface. The implanted niobium in sapphire is in different local environments with different charge states after annealing. Higher charge states of Nb+5 and Nb+4 are distributed mainly in the near surface region due to oxidation under environment. The metallic state was caused by annealing in reducing atmosphere and was distributed mainly in the sub-surface region with a profile of two-peak feature. The other charge states such as Nb+2 and Nb+1 may be associated with the defects retained in sapphire and distributed to deeper distance. The concentration of each charge state of niobium with depth is also presented in this paper.

Microstructural characterization of zirconia films produced by the dual ion beam deposition technique

Abstract Zirconia films on Si(100) substrate produced by the dual ion beam technique with oxygen ion bombardment and Ar+ ion sputtering of Zr were characterized using XRD, RBS and XPS. The results of XRD show that with increasing oxygen ion beam current densities the amorphous microstructure was transformed to a crystalline microstructure: a tetragonal phase together with monoclinic and cubic phases was found. The RBS analyses show that the deposited films consist of three layers: (1) the top layer contaminated by carbon; (2) the bulk of the films with an approximately constant value of the atomic ratio Zr/O; and (3) the transition layer between the bulk of the deposited film and the substrate. Together with XPS the RBS analyses that with the increase of oxygen ion beam current ZrOx with x from 1 3 to 2 was formed.

X-ray photoelectron spectroscopic studies of the O ls state on the surface of dual ion beam deposited ZrOx films

Abstract The O ls state on the surface of dual ion beam deposited ZrOx films were studied by using x-ray photoelectron spectroscopy. Different from the bulk of the films, it was found that a new O ls peak exists on the surface, which is assigned to be due to the existence of carbon contamination.

Characterization of Ar+ irradiated ZrO2–Y2O3 films on different substrate materials

Abstract Zirconia–yttria films containing 7.0 wt% Y 2 O 3 were prepared on silicon or iron substrate by r.f. magnetron sputtering deposition followed by 40 keV Ar + ion irradiation at room temperature. The characterization of the zirconia–yttria film phase structure was carried out by X-ray diffraction (XRD) and Raman spectroscopy. It is found that the zirconia–yttria films deposited by r.f. magnetron sputtering on silicon substrate were amorphous, while monoclinic and cubic phases appeared for the films prepared by the same deposition method on iron substrate. Also films grown on the different substrates and exposed to Ar + irradiation, exhibited different phase transformation behavior.

Oxidation Behaviour of Ieabct Deposited NiCoCrAlY-ZrO 2 ·y 2 O 3 Coating

The oxidation behaviour of NiCoCrAlY-ZrO 2 ·y 2 O 3 coatings produced by using an ion-electron-atom beams combination technique (IEABCT) was studied after air exposure at 1100 °C for up to 300 hours. It was found that pores were dispersed in the coating, especially in the interface between coating and substrate, and no spallation or separation of the ceramic layer from the metallic bond layer were observed. The composition and morphology of the coatings before and after oxidation exposure in air at 1100 °C for 300 hours were examined by microscopy and electron microprobe analysis (EMPA).

Aqueous corrosion of ion beam mixed Ta films on 13% chromium steel

Abstract The effect of aqueous corrosion of ion beam mixed Ta on 13 wt% chromium steel in 1M H2SO4 or 0.1N NaCl solution has been investigated. The results show that Ta ion mixing can evidently improve the corrosion resistance of chromium steel. The corrosion resistances of the ion beam mixed Ta films are affected by the nature of the substrates. Some suggestions are proposed according to microanalysis results by using SEM, RBS and XPS techniques.