Helium-containing Ti films are prepared using magnetron sputtering in the helium–argon atmosphere. Isochronal annealing at different temperatures for an hour is employed to reveal the behaviour of helium bubble growth. Ion beam analysis is used to measure the retained helium content. Helium can release largely when annealing above 970 K. A thermal helium desorption spectroscopy system is constructed for assessment of the evolution of helium bubbles in the annealed samples by linear heating (0.4 K/s) from room temperature to 1500 K. Also, Doppler broadening measurements of positron annihilation radiation spectrum are performed by using changeable energy positron beam. Bubble coarsening evolves gradually below 680 K, migration and coalescence of small bubbles dominates in the range of 680–970 K, and the Ostwald ripening mechanism enlarges the bubbles with a massive release above 970 K.

研究了用He/Ar混合溅射气体的直流磁控溅射制备钛膜中He的掺入现象.分析结果表明,大量的He原子(He/Ti原子比高达56%) 被均匀地引入到Ti膜中,He含量可由混合溅射气体的He分量精确控制.通过调节溅射参数,可实现样品中He的低损伤引入.研究还发现,溅射沉积的含氦Ti膜具有较高的He成泡剂量和高的固He能力,这可能是溅射沉积形成了纳米晶Ti膜所致.纳米晶Ti膜较粗晶材料具有很高浓度的He捕陷中心,使He泡密度增大而泡尺寸减小.随He引入量的增加,Ti膜的晶粒尺寸减小,He引起的晶体点阵参数和X射线衍射峰宽度增大,晶体的无序程度增加.

The incident angle dependence of secondary electron emission induced by a swift H-2(+) ion impinging on carbon is studied using the Monte Carlo method combined with the semiempirical theory. The relationships both between the electron emission yield and the project angle and between the statistics and the projectile angle are investigated. The results show that the backward electron emission yield deviates from the inverse cosine law, due to the effect of the valence electrons of H-2(+). The ratio of the forward electron emission yield to the backward electron emission yield at the inclining incidence is different from that at the normal incidence. The statistical distribution of electron emission is independent of the incident angle. The value of b, the deviation parameter from the Poisson distribution, increases with projectile energy.

RBS/Channeling,Sputtering/RBS and SIMS analysis have been performed on the MBE grown Si/Ge x Si 1- x multilayer.The thickness,atomic ratio and crystalline perfectness of the epitaxial layer are determined by 2 MeV 4He + RBS/Channeling analysis.By sputter etching of the sample with low energy Ar + ions,the thickness of epitaxial layer is reduced.Then RBS analysis of 2 MeV 4He + ions on the etched sample yields information about the deeper layers, the interface of the multilayer samples and the concerned phenomena induced by sputter etching.The periodical structure of Si/Ge x Si 1- x multilayer samples is clearly identified by the SIMS analysis before and after sputter etching.

The hydrogenation properties of Zr samples with and without an Ni overlayer under various plasma conditions were investigated by means of non-Rutherford backscattering and elastic recoil detection analysis. The theoretical maximum hydrogen capacity, 66.7 at%, could be achieved at a hydrogen absolute pressure of ~2 Pa and a substrate temperature of ~393 K for a plasma irradiation of only 10 min; this was significantly greater than that for gas hydrogenation under the same hydrogen pressure and substrate temperature. It was also found that the C and O contamination on the sample surface strongly influences the hydrogenation, and that the maximum equilibrium hydrogen content drops dramatically with the increasing total contamination. In addition, the influence of the Ni overlayer on the plasma hydrogenation is discussed.

The depth profile of deuterium in β phase Ti 32Mo 5Nb alloy, the phase structure of alloy before and after absorbing deuterium are investigated by means of enhanced proton backscattering spectrometry and X ray diffraction, respectively. The results show that, at lower temperature, the rate of alloy absorbing deuterium is markedly higher than that in pure titanium; the mean atomic ratio of deuterium to titanium is as large as 2.5, and a portion of deuterium and titanium in Ti 32Mo 5Nb alloy forms compound TiD 1.971 and remaining portion of deuterium is dissolved in the alloy.

Hydrogenation property of Ti-Mo alloy films and the influences of C and O con- tamination on hydrogen uptake were investigated by elastic recoil detection(ERD) and high-energy non-Rutherford backscattering methods.The results show that not only the C contamination in the alloys can be reduced greatly and also the considerable upgrade in hydrogenation capability has been obtained, as compared with pure Ti. On the other hand, there is only a little increase in their storage capability with increasing Mo concentration, and the phases in the samples hydrogenated at 473 K are composed of a δ-hydride and a β-solid solution. When the Mo content approached to 20(atomic fraction,%), only the δ-phase existed in the film and the hydrogen concentration is about 45 (atomic fraction,%), the durability of the sputtered films on Mo substrate against the hydrogen absorption desorption cycle was measured, which showed a significant improvement.

介绍了一种ECR微波放电和脉冲激光沉积相结合低温沉积AlN薄膜的新方法.在ECR氮等离子体环境中用脉冲激光烧蚀Al靶,以低于80℃的衬底温度在Si衬底上沉积了AlN薄膜.结合样品表征和等离子体光谱分析,探讨了膜层沉积的机理,等离子体中活性氮物质的存在是Al-N化合的重要因素,等离子体对衬底的辐照促进膜层的形成.

The carbon and oxygen contamination on Ti surface strongly influences the hydrogen absorption and desorption capability, and even can completely passivate the surface. The effect of C and O on Ti films is investigated by high energy nonrutherford backscattering and elastic recoil detection. The experiment results show that the concentration gradient in the region of about 300 nm near the surface is very large due to the joint contamination of about 1 26×10 16 cm -2 C and 2 5×10 16 cm -2 O, and thermal releasing temperature is also increased greatly. Thin Ni film coated on the Ti film may considerably improve the hydrogen absorption and desorption capability.

The kinetics of hydrogen adsorption on thin films in the two phase regions are studied. It can be classified as four steps: dissociation of hydrogen molecule and chemisorption on the gas/solid interface, surface penetration of hydrogen atoms, diffussion of hydrogen atoms through the hydride layer as well as hydride formation at the metal/hydride interface. It is shown by theoretical and experimental results that at low pressure, hydriding rate controlling step is mainly chemisorption, and at higher pressure( p H 2  p eq ) and approaching equilibrium of system, one of the other steps becomes rate determining step.

12 Mev 16O ions were used for profile of 4He by elastic recoil detection (ERD). The sample was titanium deposited by vapor on Mo substrate. Helium was introduced in it by 20 and 40 keV implantation. The depth profile of ERD was compared with that of proton non-Rutherford backscattering (PBS). The double-peak profile was found in the sample with 40 keV implantation, but no such profile in the sample with 20 keV implantation. The results were compared with TRIM95 calculation.

Functional gradient materials (FGM) was deposited by plasma enhanced chemical vapor deposition (PECVD). The depth profile of oxygen in FGM SiOxNy was measured by using 4He-O resonance scattering. The results show that the oxygen compositions vary with depth cyclically. Another important basis for testing and verifying the refractive index with depth cyclically in the sample has been provided. The measurement method is quite effective for testing the oxygen composition in the films.

The functional gradient material (FGM) was deposited by plasma enhanced chemical vapor deposition (PECVD) controlled by computer. The depth profile of oxygen in FGM SiO xN y has been measured using 4 He O resonance scattering. The result show that the oxygen compositions vary with depth cyclically.It has been provided another important basis for testing and verifying the refractive index varied with depth cyclically in the sample and verified that the measurement method is quite effective for testing the oxygen composition in the films.

Deuterium behaviour in TiD x/Mo was investigated by ion beam analysis of nuclear reaction analysis (NRA), elastic recoil detection (ERD), Rutherford backscattering (RBS). Result shows that deuterium is uniform in titanium deuteride which is chemisorbed. In the surface of TiD x/Mo film, there is an oxidized layer with the content of oxygen atoms 1.4��10 17 cm -2. At the decomposition temperature (343��C) of titanium deuteride, the diffusion coefficient of deuterium is 2.3��10 -8 cm 2/s, and the surface recombination coefficient is 1.9��10 -27 cm 4/s. The relationship between the diffusion coefficient and annealing temperature is D=D 0e -E/kT. Recombination coefficient decreases with the increasing of contents of oxygen in the surface, and increases when a copper thin film (about 80nm) is evaporated on to the same TiD 1.5/Mo sample.

Arsenic ions have been implanted into Si at an incident energy of 3MeV or 5MeV to a dose of 1��10 16cm -2. Buried conductive layers are formed in Si substrate after annealing at 1050��C for 20s. Infrared (IR) reflection spectra in the wavenumber range of 500-4000cm -1 are measured and interference fringes related to free-carrier plasma effects are observed. By detailed theoretical analysis and computer simulation of the IR reflection interference spectra, the depth profile of the carrier density, the carrier mobility near maximum carrier density, and the carrier activation efficiency are obtained. The physical interpretation of the results and a critical discussion of the sensitivity of data fitted to the variation in parameters are given.

The relative cross sections for non-Rutherford backscattering of 4He ions from carbon atoms at the energy of 2.0–9.0 MeV were measured at a backscattering angle ϑlab = 165°. The results are presented in both graphical and numerical form with typical uncertainties less than 3%. In addition, the feature of the well-known resonance at Er = 4.262 MeV is discussed.

Various applications of computer simulation to high energy backscattering analysis were systemetically summarized. With the aid of the data measured in the accelerator lab at Fudan Univ, the data base of the computer simulation program RUMP is renewed to make it applicable to higher energy region. Some experimental results to elucidate superiority of the simulation are given. A new approach for guick calculation of non-Rutherford backscattering cross sections based on the simulation principle is suggested and it is proved by the experimental results of 4He- 12C scattering.

An energy dependence of the axial minimum channeling yield in GexSi1-x/Si(100) Strained-layer superlattice is observed in the energy range of impinging He+ ions from 1.2 to 3.0 MeV. For [100] axial channeling, the measurements are in agreement with what have been known in a single crystal. However, for [110] axial channeling, it is found that the minimum channeling yields increase markedly with the increase of He+ ion energy, which is contrary to the general channeling behaviors in a single crystal. A tentative model is suggested to explain this aberrance.

An experimental apparatus for studies of MeV ion beam modification of materials has been established on a 3 MV tandem accelerator at Fudan university. A system of X-Y electrostatic scanning implantation of MeV heavy ions and in situ Rutherford. backscattering analysis was included in it. The uniformity of scanning implantation was checked by the RBS measurement of a Si wafer implanted with 1 MeV Au ions. MeV ion beam mixing of Au/Si, Au/Ge and Ag/Si systems was preliminarily studied. The samples were irradiated by certain fluences of 1 MeV Ag ions at room temperature. The mixed layers were analyzed in situ using the glancing RBS technique with 2 MeV 4He+ ions. For Au/Si system, a uniformly mixed layer with a defined composition is obtained, and the intermixing is much less for Ag/Si system than for Au/Si system.