Influence of Ti on Microstructure and Magnetic Properties of FePt Granular Films

在室温下,应用对靶直流磁控溅射设备在普通玻璃基片上制备了FePt(30 nm)／Ti(t nm)颗粒膜样品,随后,在真空中进行了原位退火。详细研究了Ti衬底层对FePt颗粒膜的微结构和磁特性的影响。X射线衍射图谱表明样品形成了较有序的L10织构,Ti和FePt形成了三元FePtTi合金。当Ti层厚度t=5 nm、退火温度Ta=500℃时,样品具有高度有序的L10织构、小的颗粒尺寸和优异的磁特性。矫顽力超过了6．7 kOe,饱和磁化强度为620emu／cc。并且具有较小的开关场分布。结果表明FePt／Ti颗粒膜系统可作为超高密度磁记录介质的候选者。

Effect of bias voltage on microstructure and nanomechanical properties of Ti films

In order to investigate nanomechanical properties of nanostructured Ti metallic material, pure Ti films were prepared by magnetron sputtering at the bias voltage of 0-140 V. The microstructure of Ti films was characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and high-resolution transmission electron microscopy（HRTEM）. It is interesting to find that the microstructure of pure Ti films was characterized by the composite structure of amorphous-like matrix embodied with nanocrystallines, and the crystallization was improved with the increase of bias voltage. The hardness of Ti films measured by nanoindentation tests shows a linear relationship with grain sizes in the scale of 6-15 nm. However, the pure Ti films exhibit a soft tendency characterized by a smaller slope of Hall-Petch relationship. In addition, the effect of bias voltage on the growth orientation of Ti films was discussed.

Preparation of Diamond-like Carbon Films on the Surface of Ti Alloy by Electro-deposition

In this paper, diamond-like carbon (DLC) films were deposited on Ti alloy by electro-deposition. DLC films were brown andcomposed of the compact grains whose diameter was about 400 nm. Examined by XPS, the main composition of the filmswas carbon. In the Raman spectrum, there were a broad peak at 1350 cm^(-1) and a broad peak at 1600 cm^(-1), which indicatedthat the films were DLC films.

Wear-resisting Oxide Films for 900℃

A study was conducted to develop low-friction, wear-resistant surfaces on high temperature alloys for the temperature range from 26℃ to 900℃. The approach investigated consists of modifying the naturally occurring oxide film in order to improve its tribological properties. Improvement is needed at low temperatures where the oxide film, previously formed at high temperature, spalls due to stresses induced by sliding. Experiments with Ti, W and Ta additions show a beneficial effect when added to Ni and Ni-base alloys. Low friction can be maintained down to 100℃ from 900℃. For unalloyed Ni friction and surface damage increases at 400℃ to 500℃. Two new alloys were perpared based on the beneficial results of binary alloys and ZrO2 diffusion in Ni.Low friction at temperature above 500℃ and reasonable values (0.32~0.42) at low temperature are obtained.

Microstructure and magnetic properties of Ti/Co/Ti films

The two series of as-deposited and annealed Ti/Co/Ti thin films were deposited by magnetron sputtering onto glass substrates at room temperature. The structural and magnetic properties of the films at room temperature were investigated as function of Co layer thickness. X-ray diffraction (XRD) profiles show Co nanograins are formed as the hexagonal-close-packed (hcp) structure. The perpendicular coercivity of the Ti(15 nm)/Co(30 nm)/Ti(15 nm) film annealed at 450 ℃ for 30 min is about 288 kA·m-1.

High Refractive Index Ti3O5 Films for Dielectric Metasurfaces

Ti33O55 films are deposited with the help of an electron beam evaporator for their applications in metasurfaces. The film of subwavelength （632nm） thickness is deposited on a silicon substrate and annealed at 400℃. The ellipsometry result shows a high refractive index above 2.5 with the minimum absorption coefficient in the visible region, which is necessary for high efficiency of transparent metasurfaces. Atomic force microscopy analysis is employed to measure the roughness of the as-deposited films. It is seen from micrographs that the deposited films are very smooth with the minimum roughness to prevent scattering and absorption losses for metasurface devices. The absence of grains and cracks can be seen by scanning electron microscope analysis, which is favorable for electron beam lithography. Fourier transform infrared spectroscopy reveals the transmission and reflection obtained from the film deposited on glass substrates. The as-deposited film shows high transmission above 60%, which is in good agreement with metasurfaces.

Antibacterial Activity of TiO₂/Ti Composite Photocatalyst Films Treated by Ultrasonic Cleaning

In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.

Photoelectrocatalytic activity of two antimony doped SnO_2 films for oxidation of phenol pollutants

Two types of Sb-doped SnO2 films on titanium substrate were prepared by the combination of electro-deposition and dip-coating (Ti/SnO2-Sb2O4/SnO2-Sb2O4) and single dip-coating (Ti/SnO2-Sb2O4), respectively. The surface morphology and crystalline structure of both film electrodes were characterized using X-ray diffractometry(XRD) and scanning electron microscopy(SEM). XRD spectra indicate that the rutile SnO2 forms in two films and a TiO2 crystallite exists only in Ti/SnO2-Sb2O4 electrode. SEM images show that the surface morphology of two films is typically cracked-mud structure. The photooxidation experiment was proceeded to further confirm the two electrode activity. The results show that the photoelectrocatalytic degradation efficiency of Ti/SnO2-Sb2O4 electrode with sub-layer is higher than that of simple Ti/SnO2-Sb2O4 electrode using phenol as a model organic pollutant. The Ti/SnO2-Sb2O4/SnO2-Sb2O4 photoanode has a better photoelectrochemical performance than Ti/SnO2-Sb2O4 photoanode for the removal of organic pollutants from water.

Microstructure and abrasive wear behaviour of anodizing composite films containing Si C nanoparticles on Ti6Al4V alloy

Anodized composite films containing Si C nanoparticles were synthesized on Ti6Al4 V alloy by anodic oxidation procedure in C4O6H4Na2 electrolyte. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS) were employed to characterize the morphology and composition of the films fabricated in the electrolytes with and without addition of Si C nanoparticles. Results show that Si C particles can be successfully incorporated into the oxide film during the anodizing process and preferentially concentrate within internal cavities and micro-cracks. The ball-on-disk sliding tests indicate that Si C-containing oxide films register much lower wear rate than the oxide films without Si C under dry sliding condition. Si C particles are likely to melt and then are oxidized by frictional heat during sliding tests. Potentiodynamic polarization behavior reveals that the anodized alloy with Si C nanoparticles results in a reduction in passive current density to about 1.54×10-8 A/cm2, which is more than two times lower than that of the Ti O2 film(3.73×10-8 A/cm2). The synthesized composite film has good anti-wear and anti-corrosion properties and the growth mechanism of nanocomposite film is also discussed.

Ti-Si-N films prepared by magnetron sputtering

A film growth mechanism, expressed in terms of depositing hard films onto the soft substrate, was proposed. Multicomponent thin films of Ti-Si-N were deposited onto Al substrate with a double-target magnetron sputtering system in an Ar-N 2 gas mixture. The Ti-Si-N films were investigated by characterization techniques such as X-ray diffraction (XRD), atomic force microscope (AFM), electron probe microanalyzer (EPMA), scratch test and nanoindentation. The as-deposited films have a good adhesion to Al substrate and appear with smooth and lustrous surface. The films show nanocomposite structure with nano TiN grains embedded in an amorphous SiN x matrix. The maximum hardness of the films was achieved as high as 27 GPa. The influences of the N 2 flow rate and substrate temperature on the growth rate and quality of the films were also discussed. For all samples, the Ar flow rate was maintained constant at 10 ml min 1 , while the flow rate of N 2 was varied to analyze the structural changes related to chemical composition and friction coefficient. The low temperature in the deposited Ti-Si-N films favors the formation of crystalline TiN, and it leads to a lower hardness at low N 2 flow rate. At the same time, the thin films deposited are all crystallized well and bonded firmly to Al substrate, with smooth and lustrous appearance and high hardness provided. The results indicate that magnetron sputtering is a promising method to deposit hard films onto soft substrate.

Effect of Annealing on Ferroelectric Properties of Bi_ (3.25)La_(0.75)Ti_3O_ (12) Thin Films Prepared by the Sol-gel Method

Bi3.25La0.75Ti3O12（BLT）thin films were prepared on Pt/Ti/SiO2/Si substrate by the sol-gel method.The effect of annealing on their structures and ferroelectric properties was investigated.The XRD patterns indicate that the BLT films annealed at different temperatures are randomly orientated and the single perovskite phase is obtained at 550℃.The remmant polarization increnses and the coercive field decreases with the annealing temperature increasing.The leakage current density of the BLT films annealed at 700℃ is about 5.8×10^-8A/cm^2 at the electrie field of 250kv/cm.

Preparation and Anti-Oxidation Properties of Ti(CN) Films Deposited by P CVD

Using metallo-organatic compound TPT as the source of Ti, H13 mould steels were coated with Ti(CN) films by plasma-assisted chemical vapor deposition (PCVD) and the properties of Ti(CN) films were studied. Under the appropriate temperature and pressure, Ti(CN) films on H13 mould steel surfaces had the highest micro-hardness of HV1760 at 500°C, and the films showed excellent anti-oxidation property below 500°C. The lifetime of Ti(CN)-coated augers and dies could be enhanced 7 and 4 times longer than those of untreated respectively.

Growth of Free-standing Diamond Films on Graphite Substrates with Ti Interlayers

Free-standing diamond films, deposited using DC Arc Plasma Jet CVD method onto graphite substrates with titanium interlayers, have been investigated. The Ti interlayers were deposited by arc ion plating equipments. The thickness, morphology and composite phase of Ti interlayers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The titanium carbide (TiC) was detected in both sides of the interlayers, which played an important role with respect to reasonable adhesion with film and diamond nucleation. The semi-translucent diamond films were characterized by SEM and Raman spectrum. The sharp diamond peak with low intensity of amorphous carbon shows that diamond films have very high quality. The overall results suggest that plating Ti interlayer on graphite substrate is an effective way to obtain optical grade free-standing diamond films.

Influence of Annealing Time on the Microstructure and Properties of Pb(Zr_(0.53)Ti_(0.47))O_3 Thin Films

The PZT thin films were prepared on （111）- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb（CH3COO）2], zirconium nitrate [Zr（NO3）4] were used as raw materials. The X-ray diffractometer （XRD） and scanning electron microscopy （SEM） were used to characterize the phase structure and surface morphology of the films annealed at 650 ~C but with different holding time. Ferroelectric and dielectric properties of the films were measured by the ferroelectric tester and the precision impedance analyzer, respectively. The PZT thin films were constructed with epoxy resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer （DMA）. The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins-annealed film shows peak value of 0.9, hi^her than the pure epoxy resin.

Electrochromic Properties of Sputtered Ti-Doped WOa Films

Ti-doped WO3 films were prepared by the mid-frequency dual-target magnetron sputtering method. The structure and electrochromic properties of the Ti-doped WO3 films were analysed by X-Ray diffraction （XRD）, Raman spectroscopy, spectrophotometer, cyclic chronoam- perometry and atomic force microscopy （AFM）. The results indicate that the erystallinity decrease after the doping of titanium, the channels for ion injection and extraction increase, the responding speed with 5.1% titanium doped becomes faster, and its circle life increases more than four times compared with the undoped WO3 film. In the coloured state, the W-O-W bonds decrease, but the W = O bonds increase. Since the W-O-W bonds break down for Li＋ ions＇ injection and more W = O bonds form, it is more convenient to inject Li＋ ions into the Ti-doped film than undoped film because more W-O-W bonds break down in the coloured state.

EIS Characterization of Sealed Anodic Oxide Films on Titanium Alloy Ti-10V-2Fe-3Al

Anodic oxide films grown on titanium alloy Ti-10V-2Fe-3Al in the solution of sodium tartrate, then sealed in boiling deionised water and calcium acetate solution were observed by using field emission scanning electron microscopy （FE-SEM）, and were chemically analysed by using energy dispersive spectroscopy （EDS）. Corrosion behaviour was investigated in a 3.5% sodium chloride solution, using electrochemical impedance spectroscopy （EIS）. The morphology of the anodic oxide films was dependent on the sealing processes. The surface sealed in calcium acetate solution presented a more homogeneous and smooth structure compared with that sealed in boiling deionised water. The corrosion resistance of the oxide films sealed in calcium acetate solution was better than that sealed in boiling deionised water.

Influences of nitrogen flow rate on the structures and properties of Ti and N co-doped diamond-like carbon films deposited by arc ion plating

In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti-C-N films are investigated systematically by field emission scanning electron mi- croscopy （FE-SEM）, x-ray photoelectron spectroscopy （XPS）, grazing incident x-ray diffraction （GIXRD）, Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti（C,N） phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti（C,N） phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.

Nanodiamond films deposited at moderate temperature on pure titanium substrate pretreated by ultrasonic scratching in diamond powder suspension

Nanocrystalline diamond （NCD） film deposition on pure titanium and Ti alloys is extraordinarily difficult because of the high diffusion coefficient of carbon in Ti, the large mismatch in their thermal expansion coefficients, the complex nature of the interlayer formed during diamond deposition, and the difficulty to achieve very high nucleation density. In this investigation, NCD films were successfully deposited on pure Ti substrate by using a novel substrate pretreatment of ultrasonic scratching in a diamond powder-ethanol suspension and by a two-step process at moderate temperature. It was shown that by scratching with a 30-μm diamond suspension for 1 h, followed by a 10-h diamond deposition, a continuous NCD film was obtained with an average grain size of about 200 nm. Detailed experimental results on the preparation, characterization, and successful deposition of the NCD films on Ti were discussed.

Effect of La Doping on Microstructure and Ferroelectric Prop-erties of Bi_4Ti_3O_(12) Thin Films Prepared by Sol-gel Method

The Bi4Ti3Oi2 and Bi3.25La0.75Ti3O12 thin films were prepared on the Pt/Ti/SiO2/Si substrate using the sol-gel method. The effect of La doping on the microstructure and ferroelectric properties of Bi4Ti3O12 films were investigated. Both the Bi4Ti3O12 and Bi3.25La0.75Ti3O12 thin films exhibited typical bismuth layered perovskite structure. The 2Pr （remanent polarization） value of Bi3.25La0.75Ti3O12 thin films is 18.6 μC/cm^2, which is much larger than that of Bi4Ti3O12 thin films. And the Bi3.2eLa0.75Ti3O12 films show fatigue-free behavior, while the Bi4Ti3O12 thin films exhibit the fatigue problem. The mechanism of improvement of La doping was discussed.

Electrochemical Properties of Poly(ethylene oxide)(PEO) Doped TiO_2-PEO Films Prepared by Sol-gel Dip Coating Technique

PEO modified Ti02 -PEO organic-inorganic hybrid thin films were prepared via, sol-gel dipping process on glass substrate pre-coated with ITO. The preparation parameters were studied. Electrochemical and optical properties of the films were characterized by cyclic voltammetric response and visible transmittance. X-ray diffraction (XRD) was used to determined the crystalline structure of the gel. The results show the sols added with PEO have acceptable stable periods for practical use. The PEO modified optical transitivity of the hybrid films has heavy effects on the crystallization of TiO2 during structural evolution because of the interaction between PEO and Ti02 . PEO-TiO2 films have better electrochemical activity than the TiO2 equivalent behaved as higher Li + insertion/extraction current density and cyclic reversibility.