Mo SILTCIDE SYNTHISIS BY DUAL ION BEAM DEPOSITION

Mo silicides Mo_5Si_3 with high quality were prepared using ion beamdeposition equipment with two Filter Metal Vacuum Are Deposition (FMEVAD). When the number ofalternant deposition times was 198, total thickness of the coating is 40nm. The coatings withdroplet free can be readily obtained, so the surface is smooth. TEM observation shows that Mo and Sialternant deposition coating is compact structure. The fine Mo silicide grains densely distributedin the coating. The coating adherence on silicon is excellent.

Effects of SiO_2 and TiO_2 on resistance stabilities of flexible indium-tin-oxide films prepared by ion assisted deposition

Inorganic buffer layers such as SiO2 or TiO2 and transparent conductive indium-tin-oxide （ITO） films were prepared on polyethylene terephthalate （PET） substrates by ion assisted deposition （IAD） at room temperature, and the effects of SiO2 and TiOzon the bending resistance performance of flexible ITO films were investigated. The results show that ITO films with SiO2 or TiO2 buffer layer have better resistance stabilities compared to ones without the buffer layer when the ITO films are inwards bent at a bending radius more than 1.2 cm and when the ITO films are outwards bent at a bending radius from 0.8 cm to 1.2 cm. 1TO films with SiO2 buffer layer have better resistance sta- bilities compared to ones with TiO2 buffer layer after the ITO fdms are bent several hundreds of cycles at the same bending radius, for the adhesion of SiO2 is stronger than that of TiO2. The compressive stress resulted from inward bending leads to the formation of more defects in the ITO films compared with the tensile stress arising from outward bending. SiO2 and TiO2 buffer layers can effectively improve the crystallinity of ITO films in （400）, （440） directions.

CORROSION BEHAVIOR OF Cu-Nb AND Ni-Nb AMORPHOUS FILMS PREPARED BY ION BEAM ASSISTED DEPOSITION

The Cu25 Nb75 and Ni45Nb55 amorphous films with about 500nm thickness were prepared by ion beam assisted deposition (IBAD). Potentiodynamic polarization measurement was adopted to investigate the corrosion resistance of samples and the tests were carried out respectively in 1mol/L H2SO4 and NaOH aquatic solution. The corrosion performance of the amorphous films was compared with that of multilayered and pure Nb films. Experimental results indicated that the corrosion resistance of amorphous films was better than that of the corresponding multilayers and pure Nb films for both Ni-Nb system with negative heat of formation and Cu-Nb system with positive heat of formation.

AMORPHIZATION IN Nb-M (M=Fe, Co, Ni) BINARY METAL SYSTEMS INDUCED BY ION BEAM ASSISTED DEPOSITION (IBAD)

Ion beam assisted deposition technique (IBAD) was utilized to systematically study amorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe, Co or Ni). The glass forming range termed as Nb fraction of Nb-Fe system was about 34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at. % to 80at. %. Similar percolation patterns were found in amorphous alloy films. The fractal dimensions of the percolation patterns approach to 2, which indicates 2-D layer growth for amorphous phases. It is regarded that the assisted Ar+ ion beam during the deposition process plays important role for the 2-D layer growth. Some metastable crystalline phases were obtained in these three systems by IBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc and hcp phases in Nb-Co and Nb-Ni systems. The formation and competing between the amorphous and the metastable crystalline phases were determined by both the phases' thermodynamic states in binary metal systems and kinetics during IBAD process.

Structure and Tribological Property of TiBN Nanocomposite Multilayer Synthesized by Ti-BN Composite Cathode Plasma Immersion Ion Implantation and Deposition

A Ti-BN complex cathode is made from Ti and h-BN powders by the powder metallurgy technology, and TiBN coating is obtained by plasma immersion ion implantation and deposition with this Ti-BN composite cathode. The TiBN coating shows a self-forming multilayered nanocomposite structure while with relative uniform elemental distributions. High resolution transmission electron microscopy images reveal that the multilayered structure is derived from different grain sizes in the nanocomposite. Due to the existence of h-BN phase, the friction coefficient of the coating is about 0.25.

Tribological Properties of DLC Film Prepared by C^+ Ion Beam-assisted Deposition (IBAD)

C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.

The Effects of Annealing and Discharging on the Characteristics of MgO Thin Films Prepared by Ion Beam-Assisted Deposition as a Protective Layer of AC-PDP

This study investigated the effects of annealing and discharging on the characteristics of MgO thin films prepared by ion beam-assisted deposition as a protective layer of AC-PDP. By an annealing process at a temperature of 450 ℃ for more than three hours, the crystallinity of the deposited MgO films was improved, but the surface of the （200）-oriented MgO thin films in the vicinity of the discharge electrodes, especially on the inner sides of the electrodes, was subjected to crack formation to the compressive stress of The failure mechanism of the MgO films plus the additional （200）-oriented MgO films was due compressive stress induced by the differences in the coefficient of thermal expansion between the electrode and the dielectric layer. In the discharging process, all MgO films were eroded unevenly, and the serious erosion occurred near the edges of the discharge electrodes. ATM（atomic force microscopy） images show that the eroded surface of the （200）-oriented MgO thin film is smoother than that of the （111）-oriented fihn. Also, the （200）-oriented MgO thin film shows an improved ability to resist ion erosion compared to the （111）-oriented film.

A New hcp Phase Formed in the Ni-Nb System during Ion-beam-assisted Deposition

The Ni80Nb20 films were prepared by ion beam assisted deposition (IBAD) with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 keV to 8 keV. When bombarded by Ar+ ions of 8 keV during deposition, a new crystalline phase with hcp structure was obtained, of which the lattice parameters are a=0.286 nm and c=0.483 nm, different from those of the similar A3B-type hcp phase previously reported. The experimental results were discussed in terms of thermodynamics and restricted kinetic conditions in the far-from-equilibrium process of IBAD. The formation of hep phase may also be related to the valence electron effect.

Density behaviors of Ge nanodots self-assembled by ion beam sputtering deposition

Self-assembled Ge nanodots with areal number density up to 2.33× 1010 cm-2 and aspect ratio larger than 0.12 are prepared by ion beam sputtering deposition. The dot density, a function of deposition rate and Ge coverage, is observed to be limited mainly by the transformation from two-dimensional precursors to three-dimensional islands, and to be associated with the adatom behaviors of attachment and detachment from the islands. An unusual increasing temperature dependence of nanodot density is also revealed when a high ion energy is employed in sputtering deposition, and is shown to be related to the breaking down of the superstrained wetting layer. This result is attributed to the interaction between energetic atoms and the growth surface, which mediates the island nucleation.

Li–N dual-doped ZnO thin films prepared by an ion beam enhanced deposition method

Li-N dual-doped ZnO films [ZnO：（Li,N）] with Li doping concentrations of 3 at.%-5 at.% were grown on a glass substrate using an ion beam enhanced deposition （IBED） method. An optimal p-type ZnO：（Li,N） film with the resistivity of 11.4 Ω·cm was obtained by doping 4 at.% of Li and 5 sccm flow ratio of N2. The ZnO：（Li,N） films-exhibited a wurtzite structure and good transmittance in the visible region. The p-type conductive mechanism of ZnO：（Li,N） films are attributed to the Li substitute Zn site （Lizn） acceptor. N doping in ZnO can forms the Lii-No complex, which depresses the compensation of Li occupy interstitial site （Lii） donors for Lizn acceptor and helps to achieve p-type ZnO：（Li,N） films. Room temperature photoluminescence measurements indicate that the UV peak （381 nm） is due to the shallow acceptors Lizn in the p-type ZnO：（Li,N） films. The band gap of the ZnO：（Li,N） films has a red-shift after p-type doping.

Deposition of diamond like carbon films by using a single ion gun with varying beam source

Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.

PREPARATION OF TiN FILMS BY N_2 ASSISTED Xe^+ ION BEAM ENHANCED DEPOSITION AND THEIR MECHANICAL PROPERTIES

A new method for preparation of hard TiN films has been developed by using electron beam evaporation-deposition of Ti and bombardment with 40 keV Xe^+ ion beam in a N_2 gas environment.The synthesized TiN films were superior to PVD and CVD ones in respects of improved adhesion to substrate and low preparing temperature.They exhibited good wear resistance and high hardness up to 2200 kg/mm^2.Some industrial applications have been reported.

Low temperature soldering alloy using Sn63 Pb37 implantation of silica ceramics and copper solder assisted by ion and deposition

Copper ion implantation and deposition technique was applied as a pretreatment method for low temperature joining of silica ceramic （ SiO2 ） and copper alloy. The effect of copper ion implantation and deposition parameters on the microstructures and mechanical behavior of the soldering joints was investigated by scanning electron microscope （SEM） , X- ray diffraction （ XRD ） and shearing test. The copper implantation depth was about 90 nm with peak concentration of 70% for the SiO2 sample implanted for 90 rain. If copper film was deposited for 4 rain using magnetron sputtering, copper layer with thickness of 150 nm and peak concentration of 80% was obtained. After pretreatment of ion implantation and deposition, SiO2 and copper were joined successfully at low temperature directly using SnPb solder. The SnPb solder filling ratio along joining seams was up to 100% without defects with smooth soldering toes. With the increase of implantation dose, the shear strength of the Si02/Cu joints increases accordingly. After a special pretreatment on SiO2 （ Cu implantation for 30min, following Cu deposition for 4 rain, then Cu implantation for 60 rain and finally Cu deposition for 120 min） , a maximum soldering strength of 22 MPa was achieved, and the soldering joints fractured at the SiO2 base material.

Cr/CrN Compound Films Prepared by Ion Beam Assisted Deposition for Improving the Performance of Bearing Steel

With the development of industry, much attention has been paid to lengthening the life span of bearings. As reported in this paper, we investigated the Cr/CrN compound films formed on the specimens of W9Cr4V2Mo bearing steel by ion beam assisted deposition for improving the performance of bearing steels. The Vicker＇s microhardness, pin-on-disc, electrochemical measurement, XRD and SEM tests were used to characterize and analyze the treated samples. All results indicated that the mechanical properties of the treated samples were good, with the microhardness greater than that of the uncoated specimen, and the wear resistance, the passivity and pitting corrosion resistance increased considerably, the films possessed alternate Cr and CrN compound phases and produced different effects on the improvement of the performance of W9Cr4V2Mo bearing steels with different composing phases.

PREPARATION OF B-N FILMS BY ION BEAM ASSISTED DEPOSITION

BN films,synthesized by ion beam assisted deposition,were analysed by RBS,AES, IR spectra and TEM.Formatiom of c-BN phase was shown not only by IR spectra at absorption peak of 1100 cm^(-1),but also by electron diffraction pattern.The results of AES demonstrate an effect of N^+ implantation near the film surface.The deposited films consist of three layers,i.e.,ion implantation layer,film layer and mixed intermediatelayer, according to the difference of concentration.The micro-Knoop hardness of the film is 25—35 GPa.

SYNTHESIS OF TiN FILM WITH ION BEAM ENHANCED DEPOSITION AND ITS PROPERTIES

The TiN films were synthesized with an alternate process of depositing titanium from a E-gun evaporation source and 40 keV N^+ bombarding onto the target.It is shown from the composi- tion analysis and structure investigations using RBS,AES,TEM,XPS and X-ray diffraction spectrum that the formed fihns are mainly composed of TiN phase with grain size of 30—40 nm and without preferred orientation,the nitrogen content in the film is much less than that in case without N^+ bombarding,and an intermixed region about 40 nm thick exists between the film and the substrate.The films exhibt high microhardness and low friction. ZHOU Jiankun,Ion Beam Laboratory,Shanghai Institute of Metallurgy,Academia Sinica, Shanghai 200050,China

Study on Blood Compatibility of Carbon-Nitride Film Synthesized by Ion Beam Enhanced Deposition

In this paper, blood compatibility of carbonnitride film synthesized by ion beam enhanced deposition is studied. Clotting time measurement, platelet adhesion test and surface energy determination were performed to evaluate the interaction between blood and material. The results show that carbonnitride film has better blood compatibility than titanium, and may be promising in biomaterial filed.

Diamond-like carbon films synthesized on bearing steel surface by plasma immersion ion implantation and deposition

Diamond-like carbon (DLC) films were synthesized by plasma immersion ion implantation and deposition (PIIID) on 9Cr18 bearing steel surface. Influences of working gas pressure and pulse width of the bias voltage on properties of the thin film were investigated. The chemical compositions of the as-deposited films were characterized by Raman spectroscopy. The micro-hardness, friction and wear behavior, corrosion resistance of the samples were evaluated, respectively. Compared with uncoated substrates, micro-hardness results reveal that the maximum is increased by 88.7%. In addition, the friction coefficient decreases to about 0.1, and the corrosion resistance of treated coupons surface are improved significantly.

Tuning the Spatially Controlled Growth,Structural Self-Organizing and Cluster-Assembling of the Carbyne-Enriched Nano-Matrix during Ion-Assisted Pulse-Plasma Deposition

Carbyne-enriched nanomaterials are of current interest in nanotechnology-related applications.The properties of these nanomaterials greatly depend on their production process.In particular,structural self-organization and auto-synchronization of nanostructures are typical phenomena observed during the growth and heteroatom-doping of carbyne-enriched nanostructured metamaterials by the ion-assisted pulse-plasma deposition method.Accordingly,fine tuning of these processes may be seen as the key step to the predictive designing of carbyneenriched nano-matrices with improved properties.In particular,we propose an innovative concept,connected with application of the vibrational-acoustic effects and based on universal Cymatics mechanisms.These effects are used to induce vibration-assisted self-organized wave patterns together with the simultaneous manipulation of their properties through an electric field.Interaction between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions serves as the additional energizing factor controlling the local pattern formation and self-organization of the nano-structures.

Structural Characterization of Thin Epitaxial GaN Films on Polymer Polyimides Substrates by Ion Beam Assisted Deposition

The Epitaxial GaN thin films have been fabricated by Ion Beam Assisted Deposition (IBAD) process using nitrogen ions with hyperthermal energies on the polyimides polymer substrates. By applying with the Reflection of High-Energy Electron Diffraction (RHEED), Scanning Electron Microscopy (SEM) and Quantum Design Physical Properties Measurement System, the behaviour of hexagonal GaN thin films is investigated. The result showed that the high quality of the deposited GaN layers kept appearing for many parameters depending on the temperature greatly. The behaviour of high quality of epitaxial GaN coating on the polyimide polymer substrates is a promising material for optoelectronic devices and semiconductor devices application.