氮化铝薄膜的制备及介电性能研究

采用直流磁控反应溅射的方法在金属铝基板表面沉积AlN薄膜。通过XRD、SEM对绝缘膜层进行了研究分析,并测试了膜层的介电性能。结果表明:在靶基距和溅射功率分别为5cm、150W,衬底温度在室温25℃~300℃内制备的AlN薄膜为六方晶型,沿c轴平行于衬底表面的(100)和(110)晶面生长。AlN薄膜表面有很多蠕虫状形态的晶粒随机地分布在膜平面内,这可能是200℃的衬底温度下AlN薄膜介电性能较好的原因。     

真空感应熔炼半导体用热轧NiCr靶微观组织和磁性能分析

采用真空感应熔炼方法制备了半导体用NiCr溅射靶,并对其开展不同变形量下的热轧,分析了NiCr合金受到热轧作用后发生的组织形态变化与磁性能改变。研究结果表明：NiCr合金中形成了呈现面心立方结构的镍基固溶体,合金受到热轧作用后发生了晶粒明显细化现象。随着热轧变形量的逐渐增大,（101）晶面择优取向程度先提高后减小,在热轧阶段组织晶粒发生了转动。随着热轧变形增加,观察到位错出现在晶粒内,部分区域发生了位错的相互缠结,晶粒内形成了小角度晶界。热轧后的试样在磁滞回线中心部位存在更多数量的磁滞回线,增大了矫顽力和剩余磁感应强度。随着热轧变形程度的提高,合金矫顽力Hc随之提高,获得更高磁透率,而剩磁Br先逐渐增大后减小,当热轧变形程度达到10%时,Br出现了迅速增大,之后Br不断下降。     

Blood compatibilities of carbon nitride film deposited on biomedical NiTi alloy

Carbon nitride (CNx) film, diamond-like carbon (DLC) film, and titanium nitride (TiN) film were deposited on biomedical NiTi alloy substrates using direct current magnetron sputtering, respectively. In order to improve the adhesive strength between the deposited hard film and the NiTi alloy, a Ti transition layer was pre-deposited firstly. We emphatically evaluated the blood compatibilities of the NiTi alloy substrate and the deposited hard films by haemolysis test and platelet conglutination test. It was shown that the blood compatibilities of NiTi alloy can be improved effectively by the deposition of hard films. In comparison with TiN and DLC film, CNx film had the best surface modification effects covering the minimum haemolysis ratio and the best anticoagulation property.     

Solid electrolyte of tantalum oxide thin film deposited by reactive DC and RF magnetron sputtering for all-solid-state switchable mirror glass

All-solid-state switchable mirror glass was prepared by magnetron sputtering. The device exhibited the multi-layer structure of Mg₄Ni/Pd/Ta₂O₅ on WO₃/ITO/glass substrate. The Mg₄Ni, Pd, and Ta₂O₅ in the device acted as optical switches, proton injector and solid electrolyte, respectively. Reactive DC magnetron sputtering was employed as a new deposition method for Ta₂O₅ electrolyte thin film for the device. The transmittance of the device, at a wavelength of 670 nm using reactive DC-sputtered Ta₂O₅ thin film, reached 0.1% (a reflective state) to 48% (a transparent state). The transmittance change occurred in less than 40 s when 5 V was applied, and the switching speed was 60 times faster than that of the device using reactive RF-sputtered Ta₂O₅ thin film.     

Study of the performance of dry methane reforming in a microchannel reactor using sputtered Ni/Al2O3 coating on stainless steel

In this study, a microchannel reactor was designed, its catalytic performance in dry methane reforming (DRM) was assessed, and the results were compared with those observed in a conventional fixed bed reactor. The catalyst was prepared in two forms, including catalyst pellets and catalyst-coated plate. The microchannel reactor had thin films of Ni/Al₂O₃ coated on stainless steel substrate via radio frequency (RF) magnetron sputtering method in various sputtering times. The fall-off rate of the catalyst-coated plates can be neglected after putting the plates under the high-temperature DRM reaction, due to the formation of firm active catalyst coatings. The performance of the samples was evaluated at different temperatures from 700 to 800 °C, at P = 1 atm, with a CH₄:CO₂ ratio of 1. The results of XRD showed that with increasing the sputtering time, there was an increase in crystallinity. As observed in FESEM images, the sample prepared with 5 min of sputtering was dense and uniform. The results of EDX not only proved the dispersion of the samples observed in XRD and FESEM analysis, but also verified the presence of the utilized elements. The temperature of 800 °C and the sample with 5 min sputtering time were selected as the optimum condition that provided the best performance. Catalytic performance was investigated in fixed bed reactor at the same GHSV; based on the results there were no significant conversions in the fixed bed reactor. The results of the stability test in the microchannel reactor showed a good performance during 30 h on stream. Therefore, Ni/Al₂O₃ thin films had a satisfactory performance in the designed microchannel. Our study shows that this type of reactor has many advantages in terms of performance, compactness, and economic concerns.     

Ionization probability of secondary ions sputtered from Si(1 1 1) and Ge(1 1 1) surfaces

We have measured the energy distributions of the secondary ions sputtered from the Si(1 1 1) and Ge(1 1 1) surfaces and investigated the ionization probabilities of sputtered Si⁺ and Ge⁺ ions for clarifying their ionization mechanisms. The observed ionization probabilities depend on the velocity of Si⁺ and Ge⁺ ions. This velocity dependence can be successfully analyzed by a theoretical expression, which was proposed originally for the metal surfaces. This implies that the ionization mechanism of Si⁺ and Ge⁺ ions is the same as ions sputtered from the metal surface, i.e., the resonant electron transfer in the high velocity regime and the thermal excitation process in the low velocity regime. The difference in the ionization probability between Si⁺ and Ge⁺ ions is well explained by the difference in the band gap energy.     

195keV Ar^＋辐照非晶态合金表面损伤形貌的研究

用扫描电子显微镜观测研究了室温下１９５ｋｅＶＡｒ＋辐照非晶态合金Ｃｏ（６０）Ｆｅ（１２）Ｎｉ（１０）Ｓｉ６Ｂ（１２）和Ｆｅ（３９）Ｎｉ（３９）Ｖ２Ｓｉ（１２）Ｂ８在各剂量阶段的表面损伤形貌。结果表明，表面损伤是发泡和溅射相互竞争的过程。低剂量下，表面损伤以发泡为主；而在高剂量时，表面发泡消失，溅射造成的多孔粗糙表面损伤结构形成。对高剂量时表面发泡消失的可能机制作了探讨。     

Angular dependence of the sputtering yield from a cylindrical track

The dependence of the sputtering yield on the incident angle, Θ, is determined using molecular dynamics (MD) simulations for a cylindrical track produced by a fast ion. For a ‘small' spike radius and for the mean energy in the track, E_exc, smaller than the binding energy, U, a (cosΘ)^−1.7 dependence is found, close to the linear collision cascade (LCC) result and to some thermal spike models. On the other hand, when E_exc>U, the incident angle dependence is (cosΘ)⁻¹. For a larger spike radius we obtain a (cosΘ)^−1.6 dependence for both high and low energy densities. Analytic spike models based on diffusive transport are shown not to give satisfactory results. In addition, at low energy densities we see correlated atom ejection ignored in analytic models. Applying the MD results to the experimental data for electronic sputtering of solid O₂ at large excitation densities suggests that the effective spike radius is larger than the initial Bohr adiabatic radius indicating that energy is rapidly transported from the initially narrow track.     

Binder free and high performance of sputtered tungsten nitride thin film electrode for supercapacitor device

Here, we demonstrates the fabrication of binder free and very efficient supercapacitor electrode based on tungsten nitride (W₂N) thin film on stainless steel (SS) substrate using reactive sputtering technique. W₂N thin film as a working electrode exhibits high specific capacitance (163 F g⁻¹ at 0.5 mA cm⁻² in 1 M H₂SO₄) along with excellent cycling stability. The binder free symmetric supercapacitor (W₂N||W₂N) device delivers a high specific capacitance (80 Fg^-1) and long life span (90.46% capacitance retention after 10,000 cycles) along with high energy (12.92 Whkg⁻¹) and power (∼674 kWkg⁻¹ at 9.36 Whkg⁻¹) densities. These observed excellent electrochemical performances of the present W₂N thin film based supercapacitor device, recommend it as a potential candidate for energy storage applications.     

磁控溅射法制备防水透湿织物的性能研究

介绍子利用磁控溅射法制备透湿织物的基本原理及方法，通过对防水透湿织物憎水性及透湿性的测试分析，发现溅射后织物的憎水性明显提高，且憎水性随溅射功能的增大而减小，随压力的增大而增在，而溅射前后的透湿性受功率和压力的影响不大。