ZnO／Ga2O3膜的氨化温度对制作硅基GaN纳米材料的影响

通过在不同温度下氨化ZnO／Ga2O3膜，在Si衬底上成功制备了GaN纳米结构材料。氨化前，ZnO层和Ga2O3膜分别通过射频磁控溅射法依次溅射到Si衬底上。用X射线衍射(XRD)、红外傅里叶变换光谱(FTIR)分析了GaN晶体的结构和组分，利用扫描电子显微镜(SEM)观察了样品的形貌。通过对测试结果的分析可知在Si衬底上由ZnO挥发辅助生长出六方纤锌矿GaN纳米结构晶体，并且ZnO／Ga2O3的氨化温度对形成GaN纳米材料具有明显的影响。     

Preparation and Properties of GaN Micro-Ribbons on Ga-Diffused Si （111） Substrates

用射频磁控溅射工艺在室温扩镓硅衬底上沉积Ga2O3膜,然后在氨气气氛下氮化Ga2O3膜得到GaN微米带,用X射线衍射(XRD)、扫描电镜(SEM)、选区电子衍射(SAED)、X射线光电子能谱(XPS)及光致发光谱(PL)对薄膜样品进行了结构、表面形貌、组分及发光特性分析.SEM图像显示直径约为100 nm～300 nm微米带随机分布在GaN薄膜表面.XRD、XPS及SAED分析表明GaN微米带呈六方闪锌矿多晶结构,择优沿[001]方向生长.P1显示了可能由量子限制效应引起的发光峰,其相对于报道的GaN晶体发光峰有显著蓝移.     

Preparation and characterization of GaN films grown on Ga-diffused Si （111） substrates

Hexagonal GaN films were prepared by nitriding Ga2O3 films with flowing ammonia. Ga2O3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. This paper have investigated the change of structural properties of GaN films nitrided in NH3 atmosphere at the temperatures of 850, 900, and 950℃ for 15 min and nitrided at the temperature of 900℃ for 10, 15, and 20 rain, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the structure, surface morphology and composition of synthesized samples. The results reveal that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained when nitrided at 900℃ for 15 min.     

Synthesis of GaN films on porous silicon substrates

A novel and simple method was employed to synthesize GaN films on porous silicon (PS) substrates. GaN films were obtained through the reaction between NH3 and Ga2O3 films deposited on the substrates with magnetron sputtering. Since GaN and PS are all good materials for luminescence, it is expected to obtain some new properties from GaN on PS. The samples were analyzed with X-ray diffraction (XRD) to identify crystalline structure. Fourier transmit infrared (FTIR) spectrum was used to analyze the chemical state of the samples. The films were observed with scanning electron microscopy (SEM) and were found to consist of many big crystal grains. Photoluminescence (PL) spectrum was used to illuminate the optical property of the GaN films.     

（Short communication） Synthesis of GaN films on porous silicon substrates

A novel and simple method was employed to synthesize GaN films on porous silicon （PS） substrates, GaN films were obtained through the reaction between NH3 and Ga2O3 films deposited on the substrates with magnetron sputtering. Since GaN and PS are all good materials for luminescence, it is expected to obtain some new properties from GaN on PS. The samples were analyzed with X-ray diffraction （XRD） to identify crystalline structure. Fourier transmit infrared （FFIR） spectrum was used to analyze the chemical state of the samples. The films were observed with scanning electron microscopy （SEM） and were found to consist of many big crystal grains. Photoluminescence （PL） spectrum was used to illuminate the optical property of the GaN films.     

Fabrication of hexagonal gallium nitride films on silicon (111) substrates

Hexagonal gallium nitride films were successfully fabricated through ammoniating Ga2O3 films deposited on silicon (111) substrates by electrophoresis. The structure, composition, and surface morphology of the formed films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The measurement results reveal that the polycrystalline GaN films with hexagonal wurtzite structure were successfully grown on the silicon (111) substrates. Preliminary results suggest that varying the ammoniating temperature has obvious effect on the quality of the GaN films formed with this method.     

氨化合成一维GaN纳米线

用氨化溅射Ga2O3薄膜的方法，成功地合成了一维GaN纳米线。用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)和高分辨电镜(HRTEM)对样品进行了分析。生成的GaN纳米线平直光滑，其直径为20nm～90nm，长可达50μm；纳米线为高质量的单晶六方纤锌矿GaN，沿[110]方向生长。用此工艺制备GaN纳米线，避免了在制备过程中引入杂质，合成的纳米线纯度较高。     

真空退火对溅射淀积ZnO：Ga透明导电膜性能的影响

采用射频磁控溅射法在玻璃衬底上低温制备出了镓掺杂氧化锌(ZnO:Ga)透明导电膜,研究了真空退火对薄膜结构、电学和光学特性的影响。结果表明:真空退火后,薄膜结构得到明显改善,电阻率由退火前的1.13×10-3?·cm下降到5.4×10-4?·cm,在可见光区的平均透过率也由未退火前的83%提高到退火后的90%以上。     

氨化Si基Ga2O3／Al2O3制备GaN薄膜

研究了Ga2O3／Al2O3膜反应自组装制备GaN薄膜。首先利用磁控溅射法在硅衬底上制备Ga2O3／Al2O3膜，再将Ga2O3／Al2O3膜在高纯氨气气氛中氨化反应得到了GaN薄膜。用X射线衍射(XRD)，X光光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)和荧光光谱(PL)对样品进行结构、组分、形貌和发光特性的分析。测试结果表明：用此方法得到了六方纤锌矿结构的GaN晶体膜。     

氨化硅基Ga2O3／Al2O3制备GaN薄膜性质研究

研究了Ga2O3／Al2O3膜反应自组装制备GaN薄膜。首先利用磁控溅射法在硅衬底上制备Ga2O3／Al2O3膜，再将Ga2O3／Al2O3膜在高纯氨气气氛中氨化反应得到GaN薄膜。用傅里叶红外谱仪(FTIR)，X射线衍射(XRD)和扫描电镜(SEM)对试样进行结构、组分和形貌分析。通过分析薄膜各方面的性质，得出了用此方法制备氮化镓薄膜的Al2O3缓冲层最佳的厚度为15nm左右，最佳氨化条件是在900℃下氨化15min。     

TiNi/ZnO复合智能薄膜的制备及性能研究

使用射频磁控溅射法在石英衬底上制备quartz/ZnO/TiNi及quartz/TiNi/ZnO复合薄膜结构,利用XRD、SEM划痕仪等测试方法研究了复合薄膜的相结构、微观组织、力学性能。利用DMA分别研究了quartz/TiNi与quartz/ZnO/TiNi复合结构的阻尼性能随振动频率及振幅的变化规律。结果表明,前者频率响应范围在10 Hz以内,后者响应范围达到20 Hz;前者的临界外加激振电压仅为0.6 V,后者的临界外加激振电压达到1.0 V。阻尼性能测试表明,quartz/ZnO/TiNi复合结构的阻尼性能优于quartz/TiNi复合结构。由划痕仪测得两种复合薄膜结构与基体的临界结合力分别为45.75和40.15 N     

基体对硅钼薄膜结构及电学性能的影响

采用射频磁控溅射法在硅基底上制备了硅钼薄膜，并研究了不同基体对薄膜相结构、表面形貌及电学性能的影响。XRD，AFM和SEM分析结果表明，硅和石英玻璃基体上沉积的硅钼薄膜为非晶，而氧化铝基体上沉积的硅钼薄膜为多晶。四探针电阻测试结果表明，随着退火温度的升高，硅基体和氧化铝基体上的硅钼薄膜其方阻逐渐降低，而石英玻璃基体上的硅钼薄膜其方阻却异常增大。     

氮化铜薄膜制备中氮气比例对其结构及微观力学性能的影响

采用射频磁控溅射方法在玻璃基底上制备氮化铜薄膜,研究了氮氩混合气体中的氮气比例对薄膜择优生长取向、表面晶粒尺寸和微观力学性能的影响。结果表明:低氮气比例时,薄膜的纳米力学性能比较差;随着氮气比例的增加,氮化铜薄膜的择优生长晶面从(111)晶面转变为(100)晶面,晶粒尺寸变小,显微硬度增加,弹性模量则是先增加,后减小。     

基于磁控溅射–氟化改性的新型ZnO/SiO2复合超疏水涂层防冰性能研究

目的 通过磁控溅射及表面氟化修饰不同纳米尺度的氧化锌(ZnO)和二氧化硅(SiO2)粒子,获得一种新型的ZnO/SiO2复合超疏水涂层。方法 研究不同氟化修饰剂对新型ZnO/SiO2复合超疏水涂层防冰性能的影响。采用光学接触角测量仪、扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)对涂层的水接触角(CA)、滚动角(SA)、微观膜层形貌以及氟化前后化学键的改变进行分析。采用自制结冰装置及数显拉力计对涂层在高湿低温环境中的结冰时间和冰层在涂层表面的黏附强度进行测试。结果 磁控溅射ZnO和SiO2纳米粒子复合制膜得到的粒子排列状态规则,并且两种不同尺寸粒子的掺混使得涂层表面呈多簇状微纳米二级结构,能够很好地降低液滴与表面的附着力;分别选用十七氟癸基三乙氧基硅烷(FAS-17)、聚二甲基硅氧烷(PDMS)、十二氟庚基丙基三甲氧基硅烷(G502)、十六烷基三甲氧基硅烷(HDTMS)4种氟化修饰剂对涂层表面进行整体修饰,其中,FAS-17修饰后的涂层表面防冰效果最好,其液–气复合接触面积比例达到了94.38%,接触角和滚动角达到最佳,分别为164.7°和3°,且冰在表面的黏附强度降低至3.8 kPa;在湿度为60%,温度分别为–2、–10及–20 ℃的条件下,涂层延缓结冰时间分别为244 6、160 4、137 s。结论 采用不同纳米尺度的ZnO和SiO2纳米粒子,经过磁控溅射和整体表面改性可以得到簇状结构的新型复合超疏水涂层。通过FAS-17乙醇溶液进行表面氟化修饰,更加显著地提高了涂层的超疏水性能。     

Au/Al_2O_3层状复合纳米涂层的制备及其抗氧化性能(英文)

采用磁控溅射法成功制备Al2O3/Au层状复合纳米涂层,所制备的涂层结构致密且由Al2O3层和Au层交替组成。采用高温循环氧化实验对复合涂层在不锈钢基体上的高温抗氧化性能进行分析评价。结果表明:Al2O3/Au层状复合纳米涂层极大地改善不锈钢基体的抗氧化和抗剥落性能。其抗氧化机理与涂层能够有效地抑制氧向合金基体的扩散并促进不锈钢基体中Cr元素的选择性氧化有关;抗剥落机理可归因于复合涂层中的Au层和纳米结构的Al2O3层能够有效地松弛高温热循环过程中产生的热应力,从而提高涂层的抗剥落性能。     

Effects of Ag layers on the SiO2/FePt thin films deposited by magnetron sputtering

The effects of Ag layers with different locations and thicknesses on the structural and magnetic property of SiO2/FePt multilayer films were investigated.The non-magnetic Ag layer plays an important role in inducing（001） orientation and ordering of FePt grains,as well as the SiO2-doping reducing the grain size and the magnetic exchange coupling between grains.When the 10 nm Ag layer is moved from the bottom to the top of the SiO2/FePt multilayer film,the coercivity gradually decreases;the largest difference between the out-of-plane coercivity and the in-plane one is obtained in the sample of [SiO2（2 nm）/FePt（3 nm）]3/Ag（10 nm）/[SiO2（2 nm）/FePt（3 nm）]2.Furthermore,the location of Ag layers was fixed and the thickness was changed.The XRD curves suggest that the intensity of the（001） peak becomes the strongest with the addition of 10 nm Ag layers.     

Effects of ZrO2 on the structure and magnetic properties of CoPt thin films

[CoPt 1.5 ml/ZrO2 xnm]10 multilayer films were deposited on glass substrates by magnetron sputtering and then annealed in vacuum at 600℃ for 30 min. Their structures and magnetic properties were investigated as a function of ZrO2 content. The results show that the grain size and coercivity first increase and then decrease with the increase in ZrO2 content. The maximum coercivity and grain size are obtained at 37 vol.% of ZrO2. The content of ZrO2 in the film plays an important role in the separation of CoPt grains and in the reduction of intergrain exchange interaction. On the basis of the studies of angular dependent coercivity, it is found that the magnetization reversal of CoPt films with （111 ） texture is different from either the domain wall motion or the S-W type of rotation mode.     

镧助剂对Pd/Al_2O_3催化剂性能的影响

一氧化碳(CO)-亚硝酸甲酯(MN)气相氧化偶联合成草酸二甲酯(DMO)的反应是煤制乙二醇的关键转化步骤,现用的Pd/Al_2O_3催化剂中钯负载量高达1%。在催化剂制备过程中添加不同助剂,用催化燃烧热阻型检测系统考察其对合成反应的催化性能影响。表征分析表明,镧助剂可改善钯在载体上的分散;当La_2O_3/Al_2O_3=14 mg/g时,La_2O_3在载体表面以单层分散,制成的催化剂中钯分散性最好。性能评价结果显示,载钯量0.2%的催化剂具有较好的稳定性,在优化反应条件下,其性能甚至优于工业催化剂。     

Nd对Al2O3f/AZ91D复合材料高温蠕变性能的影响

利用高温压缩蠕变实验研究了Nd对复合材料的高温蠕变性能以及压应力对濡变应力指数的影响.结果表明稀土元素Nd的加入可以明显改善复合材料的高温蠕变性能,试验中添加0.8％Nd的Al2O3f/AZ91D复合材料的抗高温蠕变性能最好;当应力为60～90 MPa与156～180MPa时复合材料的蠕变机理为基体和增强体之间的载荷传递,纤维的开裂和破断是其失效的主要机制;应力为90～156 MPa时复合材料的蠕变机理为位错滑移与位错攀移共同作用.