掺银离子TiO2薄膜的结构及与不锈钢基板的界面反应

采用溶胶-凝胶法在不锈钢表面制备掺银的TiO2薄膜,研究氧化处理对不锈钢表面Ag/TiO2抗菌薄膜组成和性能的影响,利用X-射线衍射谱(XRD)、扫描电子显微镜(SEM)和X-射线光电子能谱(XPS)等对经氧化处理和未经处理的不锈钢表面Ag/TiO2薄膜进行比较,研究薄膜的结构、界面反应特征及机制.发现:未经氧化处理的不锈钢由于其中的铁原子进入薄膜与TiO2反应形成钛酸铁固溶体薄膜;经氧化处理后不锈钢表面形成一层比较致密的氧化铁层,阻止了不锈钢内部的铁原子扩散进入薄膜与TiO2反应,表面同时形成钛酸铁和锐钛矿型的TiO2薄膜;锐钛矿型的TiO2与银离子反应形成钛酸银,既保持了银离子的高杀菌性能(样品的6小时抗菌率达到100%),同时又不至使金属银形成而使材料变色.在未经氧化处理的不锈钢表面,掺银TiO2薄膜中的银离子转化为单质银,抗菌性能低.     

N~ 、Xe~ 离子注入银薄膜的实验分析

实验研究了离子注入对多晶银薄膜晶体结构及表面成份的影响。在室温环境下,将能量为24keV的N~ 离子和350keV的Xe~ 离子以不同的注入剂量注入到多晶银薄膜中。对离子注入前后的银薄膜样品进行了透射电子显微镜(TEM)观察和X射线光电子能谱(XPS)及俄歇电子能谱(AES)分析。经分析发现,离子注入后在银薄膜中出现了再结晶和晶粒长大现象,而且晶粒尺寸随注入离子的剂量增加而增加。当注入的N~ 离子剂量≥1.3×10~(17)Ions/cm~2及注入的Xe~ 离子剂量达到3×10~(16)Ions/cm~2时,多晶银膜转变成单晶银薄膜。本文对实验结果进行了讨论。     

银离子注入热解碳的抗菌性研究

本文用革兰氏阳性菌-金黄色葡萄球菌和革兰氏阴性菌-大肠杆菌研究了注银医用热解碳的抗菌性。注入银离子的能量为70 keV,剂量分别为5×1014、1×10155、×1015、1×1016、5×1016ions/cm2。用卢瑟福背散射分析(RBS)和X射线光电子能谱(XPS)对注银热解碳的表面进行了微观分析。抗菌实验结果表明,样品的抗菌率随着注入剂量的增大而增大,当注入剂量高于1×1016ions/cm2时,注银热解碳对金黄色葡萄球菌和大肠杆菌的抗菌率接近100%。RBS和XPS分析结果表明,银离子注入到热解碳表层,且浓度随注入剂量的增大而增加,富银的表面层起到抑菌和杀菌作用。     

反应磁控溅射制备Ag/TiO_2复合薄膜及其银离子释放速率研究

采用反应磁控溅射法制备Ag/TiO_2复合薄膜,利用X射线衍射、扫描电镜、透射电镜、X射线光电能谱和原子吸收光谱分析了不同实验参数对复合薄膜形貌和银离子溶解释放规律。研究结果表明随着氧气流量的加大,银纳米颗粒在薄膜体相和表面的团聚和不规则分布增加;表面缓冲层对银纳米颗粒的表面偏析现象和银离子释放速率的抑制作用有限;复合薄膜中银元素的含量则对薄膜形貌和银离子释放速率有较大影响,银含量越少,银离子释放速率越慢。综合性能分析认为在复合薄膜中银含量为9%时,银纳米颗粒在薄膜内的粒径分布较为均匀,银离子释放速率也最为缓慢。     

银离子注入剂量对2Crl3Ni2不锈钢耐蚀性能的影响研究

通过测定试样的电化学极化曲线研究了银离子注入2Cr13Ni2不锈钢后的耐蚀性能.采用AES测定了试样注入层中各元素含量沿深度方向的变化规律.研究结果表明:银离子注入2Cr13Ni2不锈钢后,其耐蚀性能与注入前相近.在一定范围内,随注入剂量的增大,不镑钢的耐蚀性能逐步改善.当2×1017～4×1017ions/cm2剂量的银离子注入不锈钢后,其耐蚀性能优于未注入银离子的不锈钢.不锈钢表面及注入层内铬含量的降低是大剂量银离子注入后造成不锈钢耐蚀性能下降的主要原因.     

沉积时间对磁控反应溅射制备TiO2薄膜性能的影响

应用直流磁控反应溅射法,在玻璃基体上制备了具有光催化活性的TiO2薄膜.TiO2薄膜的厚度随沉积时间的增加而均匀增长.基体温度则在溅射的最初1h很快上升到110℃,溅射7h基体温度不超过130℃.溅射2h得到的是非晶态TiO2薄膜,而溅射3～7h制备的薄膜为锐钛矿型结构.非晶态和小晶粒TiO2薄膜的紫外一可见透射光谱谱带边沿与结晶较好的TiO2薄膜相比有明显的蓝移,薄膜的透射率随沉积时间的增加而下降.钛以四价钛的形式存在于TiO2薄膜中.TiO2薄膜的光催化活性随沉积时间争薄膜厚度的增加而有较大提高.     

银离子注入剂量对2Cr13Ni2不锈钢耐蚀性能的影响研究

通过测定试样的电化学极化曲线研究了银离子注入2Cr13Ni2不锈钢后的耐蚀性能。采用AES测定了试样注入层中各元素含量沿深度方向的变化规律。研究结果表明：银离子注入2Cr13Ni2不锈钢后,其耐蚀性能与注入前相近。在一定范围内,随注入剂量的增大,不锈钢的耐蚀性能逐步改善。当2×10^17～4×10^17ions／cm^2剂量的银离子注入不锈钢后。其耐蚀性能优于未注入银离子的不锈钢。不锈钢表面及注入层内铬含量的降低是大剂量银离子注入后造成不锈钢耐蚀性能下降的主要原因。     

银修饰氮掺杂TiO_2薄膜的制备及光催化性能研究

TiO2具有光催化活性,因而被广泛应用于废水处理、空气净化、尾气处理等领域。研究表明,经掺杂的TiO2薄膜具有更优异的光催化活性。在众多的可掺杂元素中,N和Ag具有独特的性能特征,因此其可使TiO2薄膜的光催化活性得到较大提升。本文使用直流磁控溅射法和拼靶工艺制备了不同Ag含量的银修饰掺氮TiO2薄膜,并分析了薄膜的形貌结构、表面元素化学态、光学性能和可见光催化活性。研究表明:薄膜沉积过程中Ag含量对薄膜性能影响较大。在TiO2的表面,颗粒细小而均匀。随着Ag含量的增加,薄膜表面出现凸起颗粒,为Ag2O颗粒,且其尺寸逐渐增大;薄膜对350~800 nm波段光的吸收增强。当Ag含量为6.76%(原子比)时,薄膜具有最高的可见光催化活性。     

纳米TiO2薄膜的制备及其表面形貌AFM观测

采用溶胶-凝胶法在玻璃载波片及ITO导电玻璃片上制备出负载型纳米TiO2薄膜,并用原子力显微镜(AFM)对不同条件下制备的TiO2的表面形貌进行了表征.结果表明,TiO2薄膜能较好地负载在玻片表面,并且TiO2薄膜的表面形貌与前驱物的配比浓度、基片、热处理温度等都有密切的关系.随浓度和镀膜层数的增大,薄膜中TiO2纳米微晶的颗粒尺寸逐渐增大,从细小均匀粒子膜变为较大不规则的板块结构.在ITO薄膜面形成的TiO2薄膜具有较小的颗粒和均匀的分布.     

TiO_(2-x)N_x薄膜托槽的摩擦性能研究

通过射频磁控溅射法,在不锈钢金属托槽表面制备了不同厚度的TiO2-xNx薄膜。薄膜的晶体结构,表面形貌和表面粗糙度分别通过X射线衍射、扫描电子显微镜和2206型表面粗糙度测量仪分析。通过14FW往复摩擦磨损测试仪考察薄膜托槽体外摩擦性能。结果显示,所制备的纳米TiO2-xNx薄膜为锐钛矿型,结构均匀致密。不同厚度的TiO2-xNx薄膜托槽的动、静摩擦系数不论干燥或湿润条件下均小于对照组。在同一湿性环境下,随薄膜厚度增加TiO2-x Nx薄膜托槽摩擦系数呈递减趋势。TiO2-xNx薄膜托槽表现出了良好的低摩擦性能。     

Enhancing Adhesion of Screen‐Printed Silver Nanopaste Films

The interfacial fracture energy of screen‐printed silver nanopaste films is quantitatively measured, and the fundamental adhesion mechanism is investigated. It is found that the interfacial fracture energy at the Ag film/silicon substrate interface is critically affected by the sintering condition. The sintering temperature tunes the interfacial surface morphology of Ag films and the amount of organic residues at the interface. These factors determine the degree of interfacial toughening between the Ag film and the substrate, which directly affects the adhesion properties. The increased surface roughness of the Ag film with sufficient organic residues leads to a larger interfacial toughening at the film/substrate interface, and subsequently to an enhanced interfacial fracture energy of screen‐printed Ag nanopaste films.     

ITO–Ag alloy–ITO film with stable and high conductivity depending on the control of atomically flat interface

The conductivity of ITO–Ag–ITO films declines with the deposition temperature increased above 200 °C, because the surfaces of Ag layers become rough that scatter the conduction carriers. The solid-solution Ag–Ti alloy and Ag–Ti–Cu alloy are developed to improve the stability of the surface morphology of Ag layers. This research proves that the Ag–Ti film can keep a smooth surface at an even higher deposition temperature. This leads ITO–AgTi–ITO films to have low resistivity at high deposition temperatures. However, further addition of Cu atoms into Ag–Ti films causes several spikes formed on the surfaces probably relative to the relaxation of strain energy. The conductivity of the ITO–AgTiCu–ITO film will decline when a large amount of spikes is formed on the surface of Ag–Ti–Cu layer at a high deposition temperature.     

Graphene synthesis by ion implantation

We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with controllable thickness. Thermally annealing polycrystalline nickel substrates that have been ion implanted with carbon atoms results in the surface growth of graphene films whose average thickness is controlled by implantation dose. The graphene film quality, as probed with Raman and electrical measurements, is comparable to previously reported synthesis methods. The implantation synthesis method can be generalized to a variety of metallic substrates and growth temperatures, since it does not require a decomposition of chemical precursors or a solvation of carbon into the substrate.     

超声雾化方法中两步沉积对YBCO薄膜性能的影响

用自行研制的超声雾化装置在{110}<011>织构的Ag基带上直接沉积了YBCO涂层超导薄膜, 结果发现一步沉积所得YBCO薄膜的表面有许多白色小颗粒, 而且薄膜的织构和临界电流密度都较低, 这是在900℃高温沉积过程中大量的Ag蒸发和扩散到YBCO膜层中所致. 于是本文提出分高低温两步沉积的实验方案, 即700℃先沉积15min, 再升温到900℃沉积30min, 通过SEM对薄膜表面和EDS能谱对薄膜的断面进行分析可知, 两步沉积的YBCO薄膜中Ag的含量大大降低, 而且薄膜的织构和临界电流密度得到明显改善和提高, 最后通过两步沉积制备了15cm长、临界电流密度高于10⁴A/cm²的YBCO超导薄膜.     

钛离子注入类金刚石碳膜的结构与性能的研究

使用金属离子注入的方法制备了 Ti掺杂的DLC膜。采用原子力显微镜观察了薄膜的表面形貌,Ti掺杂后 DLC 膜的表面粗糙度明显减小,表面光洁度增加,颗粒细化。拉曼光谱分析表明实验获得的薄膜是典型的DLC膜,掺杂Ti后的 DLC膜的拉曼光谱存在明显的肩峰,DLC膜化学结构中的sp2 组分增加,sp3 组分减少。透射电子显微镜分析表明Ti注入后有TiC纳米晶形成。掺入Ti的 DLC膜的硬度从 14GPa增加到 20GPa。Ti 掺杂后的 DLC 膜的摩擦系数(0.15)明显低于未掺杂的DLC膜的摩擦系数(0.21),Ti离子注入有助于提高薄膜的抗磨损性。     

等离子体基离子注入制备TiN膜的成分结构

采用Ti、N等离子体基离子注入和先在基体表面沉积纯钛层然后离子注氮混合两种方法在铝合金基体上制备了TiN膜.利用XPS分析了两种方法制备TiN薄膜的成分深度分布和元素化学价态,并用力学性能显微探针测试对比了TiN膜的纳米硬度.研究表明:两种方法制备的薄膜均由TiN组成,Ti、N等离子体基离子注入薄膜中Ti/N≈1.1,而离子注入混合薄膜中Ti/N≈1.3,Ti、N等离子体基离子注入薄膜表面区域为TiN和TiO2的混合组织,TiN含量多于TiO2,离子注入混合薄膜表面主要是TiO2;Ti、N等离子体基离子注入所制备的薄膜的纳米硬度峰值为12.26 GPa,高于离子注入混合的7.98 GPa.     

Copper/silver nanoparticle incorporated graphene films prepared by a low-temperature solution method for transparent conductive electrodes

A facile one-step co-reduction and low-temperature solution process was developed to prepare Cu–graphene (Cu–G), Ag–graphene (Ag–G), and Cu–Ag–graphene (Cu–Ag–G) composite films on glass substrates. Scanning electron microscope and transmission electron microscope images show that Cu/Ag nanoparticles are either distributed on the surface of graphene nanosheets or covered by graphene. The conductivity and transparency of these films were studied, and the results show that incorporation of Cu and Ag nanoparticles into graphene films can improve film conductivity. Ag nanoparticles are more effective in improving film conductivity. The conductivity and transparency of the composite films can be balanced by introducing the optimum amount of Cu or Ag nanoparticles. The conductivity and transparency of Cu–Ag–G films with optimum metal nanoparticle concentration are as good as those of Ag–G composite films. The Cu–Ag–G films meet the requirements of low-cost, high-conductivity, and transparent films that can be used as electrode materials. Thus, the proposed low-temperature solution process is a new route to preparing low-cost transparent and conductive electrodes on various substrates, including glass and flexible polymer substrates.     

Ag反射膜厚度对PbTe热电薄膜性能的影响

采用真空蒸发法制备相同厚度的PbTe薄膜,再利用RF磁控溅射法在上面制备不同厚度的Ag反射膜,采用XRD、SEM、FTIR和四探针法分别对制备样品的物相组成、表面形貌、透射率和电阻率进行测试,结果显示,所制备的薄膜具有明显的〈100〉方向择优取向,呈多晶结构,随着反射膜厚度的增加,薄膜结晶性能先降低后增加;晶粒尺寸增加,表面粗糙程度先降低后增加;薄膜光学性能在一定膜厚范围内,随着反射膜厚度的增加透射率降低,超过一定膜厚时,透射率降为零;随着反射膜厚度的增加,电阻率呈先急剧降低后缓慢降低的趋势。     

Crystal orientation changes of Ag thin films on the Si(111) substrate due to tribo-assisted recrystallization

Crystal orientation changes of Ag thin films due to the tribo-assisted recrystallization have been studied using grazing incidence X-ray diffraction with synchrotron radiation. After preparation of an Si(111) √3 × √3-Ag surface, a 5-nm-thick Ag film was deposited on the surface at the substrate temperature of 303 K in an ultra-high vacuum chamber. The friction experiments were carried out using a diamond pin-on-plate type tribometer just after the Ag deposition in the same UHV chamber. We found that the coefficient of friction of the Ag films on the Si(111) √3 × √3-Ag surface decreases from 0.07 to 0.03, with increasing reciprocal sliding cycles. In synchronization with the coefficient change, Ag{100} grains are gradually disappearing. As a result, the Ag{111} grains cover the entire surface after 50 sliding cycles. Moreover, we found that the domain size of the Ag{111} grains increases with increasing reciprocal sliding cycles by measuring the rocking curve width. These results directly show that the Ag(111) plane is the sliding plane of friction and the coefficient of friction of Ag films is determined by the fraction of the Ag(111) grains in the Ag films. Moreover, to clarify the reaction between the Ag film and the Si substrate due to the tribo-assisted recrystallization, the substrate strain has been studied by an extremely asymmetric X-ray diffraction technique using synchrotron radiation.     

Agglomeration behavior of Ag films suppressed by alloying with some elements

Agglomeration behavior of co-sputtered Ag-Au, Ag-Cu and Ag-Al thin films was investigated. The results showed that Ag-Au films agglomerated during annealing in a similar way to pure Ag films, but a degree of suppression of this effect was observed in Ag-Cu and Ag-Al films. In particular, no void formation was observed in Ag-Al films for annealing temperatures up to 600 °C. Different mechanisms are proposed to explain agglomeration suppression and the prevention of Ag atom migration, including the precipitation Cu atoms in Ag-Cu films, and the formation of very thin Al-oxide layers at the film surface and at the interface with the substrate. The resistivity of Ag-Au film increased by annealing due to the agglomeration, but that of Ag-Cu and Ag-Al films did not. However, the resistivity of as-deposited Ag-Al film was too high to be reduced enough by annealing.