反应磁控溅射法制备氧化钒薄膜

采用反应磁控溅射加真空退火分别在玻璃和Si（100）基底上制备氧化钒薄膜,利用X射线衍射和原子力显微镜分析其物相和表面形貌。结果表明：氧气体积分数低于15％时,玻璃上薄膜为低价钒氧化物,Si（100）A2薄膜为V2O5（001）织构和V2O3（104）织构,高于20％时两基底上薄膜均为V2O5;玻璃上V2O5薄膜500℃下退火3h生成VO2,退火后薄膜粗糙度明显下降;Si（100）上V2O5薄膜500℃下退火2h生成V2O3（104）织构,退火后薄膜粗糙度变化不大。     

反向共沉淀法制备Y2O3-ZrO2纳米晶

以乙醇为分散剂和保护剂，采用反向化学共沉淀法，制备了Y2O3-ZrO2纳米晶。结果表明：所制备的纳米晶为说办晶系；Y2O3-ZrO2纳米晶呈球形，当焙烧温度为900℃时，粒予粒径约30nm，粒径分布均匀，无明显硬团聚体存在；Y2O3-ZrO2纳米晶为多晶结构：Y2O3-ZrO2的晶化温度为489．19℃；Y2O3-ZrO2纳米晶的相对密度随粒径增大而增大。     

中频反应磁控溅射制备Al2O3:CeCl3薄膜及其光致发光特性

应用中频反应磁控溅射技术制备了Al2O3:CeCl3的非晶薄膜.Ce3+含量和薄膜的化学成分通过X射线散射能谱(EDS)测量.薄膜试样的晶体结构用x射线衍射分析.俄歇电子谱用于对薄膜材料的化学组分进行定性分析.薄膜的光致发光峰是在370 nm到405 nm范围内,它们来自于Ce3+离子的5d1激发态向基态4f1的两个劈裂能级的跃迁.发光强度强烈地依赖于薄膜中的掺杂浓度和沉积时的基片温度.薄膜发光来自于氯化铈分子中的发光中心,而不是其他的掺杂Ce3+离子.随铈含量增加,光致发光峰向低能方向移动,可能与薄膜中存在氯元素有关.     

均分散球形Y2O3：Eu^3＋纳米晶的制备

采用凝胶网格共沉淀法，以明胶为反应基质制备了单分散球形纳米Y2O3：Eu^3 荧光粉，考察了制备条件对产物粒径的影响。利用X射线衍射(XRD)、透射电子显微镜(TEM)和荧光光谱等手段对样品进行了表征。结果表明：该法制得产物为球形，一次晶粒粒径在13nm～25am之间，且粒度分布均匀，与微米晶相比，该纳米晶的激发光谱发生明显红移。     

均分散球形Y2O3：Eu^3＋纳米晶的制备研究

采用凝胶网格共沉淀法，以明胶为反应基质制备单分散球形纳米Y2O3：Eu^3 荧光粉，考察了制备条件对产物粒径的影响。利用X射线衍射(XRD)、透射电镜(TEM)和荧光光谱等手段对样品进行了表征。结果表明：该法制得产物为球形，一次晶粒粒径在13nm～25nm之间，且粒度分布均匀，与微米晶相比，该纳米晶的激发光谱发生明显红移。     

等离子辅助电子束蒸发La2O3薄膜的制备

采用等离子辅助电子束蒸发，在Si（100）衬底上沉积La2O3薄膜。随后对非晶的沉积态薄膜在750℃和900℃分别退火1h。实验结果表明，采用等离子辅助电子束蒸发，可以获得非晶态的La2O3薄膜：经750℃热处理后，薄膜部分晶化：经900℃热处理后，薄膜显著晶化，晶粒尺寸明显增大，并沿（002）方向择优取向。对薄膜厶矿特性的测量结果表明，沉积态薄膜具有较小的漏电流，但随着热处理温度升高，薄膜晶化程度提高，薄膜漏电流逐渐增大：对薄膜透过率的测量结果表明，单面抛光的Si衬底上沉积La2O3薄膜，在近红外范围内有明显的增透效果，最大可达20％左右。     

沉淀法制备纳米Eu：Y2O3荧光粉

试验分别以微米级Y2O3、Eu2O3粉体为原料，碳酸氢铵为沉淀剂，三乙醇胺为络合剂，采用三乙醇胺络合沉淀法制备了化学组成为NC6H12（NH4）Y2（CO3）（NO3）2·nH2O的前驱体。研究了前驱体在不同的煅烧温度下的物相变化，结果表明，前驱体在500℃保温2h即可直接生成立方相的Eu：Y2O3，在1000℃保温2h的条件下得到了结晶度高、分散性好、平均粒径为50～60nm、近球形的纳米Eu：Y2O3荧光粉。     

等离子辅助电子束蒸发La2O3薄膜的制备

采用等离子辅助电子束蒸发,在Si(100)衬底上沉积La2O3薄膜.随后对非晶的沉积态薄膜在750℃和900℃分别退火1 h.实验结果表明,采用等离子辅助电子束蒸发,可以获得非晶态的La2O3薄膜;经750℃热处理后,薄膜部分晶化;经900℃热处理后,薄膜显著晶化,晶粒尺寸明显增大,并沿(002)方向择优取向.对薄膜I-V特性的测量结果表明,沉积态薄膜具有较小的漏电流,但随着热处理温度升高,薄膜晶化程度提高,薄膜漏电流逐渐增大;对薄膜透过率的测量结果表明,单面抛光的Si衬底上沉积La2O3薄膜,在近红外范围内有明显的增透效果,最大可达20%左右.     

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。     

光学级金刚石自支撑膜及其镀制Y2O3增透膜后的高温抗氧化性

为了提高金刚石膜的红外透过率和高温抗氧化性能,采用纯钇(Y)金属靶,使用直流反应磁控溅射法在光学级金刚石自支撑膜表面制备了Y2O3薄膜.对比研究了光学级金刚石自支撑膜和Y2O3/Diamond/Y2O3复合窗口的高温抗氧化性能,及氧化前后样品表面形貌和红外透过率的变化情况.热分析、扫描电子显微镜和傅立叶变换红外光谱仪的研究结果表明Y2O3薄膜对光学级金刚石膜有非常好的抗氧化防护性能,在高达950℃的温度暴露30s后对光学级金刚石膜表面没有造成明显损伤,且仍能保持良好的增透效果(透过率超过80%).     

Deposition of wear resistant coatings based on diamond like carbon by unbalanced magnetron sputtering

Amorphous hydrogenerated carbon films containing a small amount of metal (Me:C-H) have been deposited by closed field unbalanced magnetron sputter ion plating. The films have graded film compositions to optimise the adhesion to the substrates, and multilayer TiC/Ti:C-H films have also been deposited. The films have excellent properties: very high measured microhardness (more than 4000 H_v), excellent adhesion (L_c 115–125 N), coefficients of friction against WC of less than 0.2, and volumetric wear rates one fifth that of titanium nitride. The coating procedure is ideally suited to the system used, and many applications for the films are already realised.     

Nanocrystalline CVD diamond coatings for drilling of WC-Co parts

Drilling of pre-sintered cemented carbide parts is a challenging task due to the high hardness and abrasive nature of the WC grains. This operation is commonly done using uncoated cemented carbide drill bits but the tool life is very limited requiring tool re-sharpening after a few holes. A solution for the improvement of the tool performance is here exploited by the use of nanocrystalline diamond (NCD) films as high abrasion resistant coatings. These coatings were grown in a hot filament chemical vapor deposition (HFCVD) reactor. Filament temperatures in the range of 1940-1980 °C were crucial to obtain highly adherent and very uniform coatings at the cutting edge and on the surfaces of the flutes. The performance of the coated tools was evaluated in through-hole drilling of a pre-sintered cemented carbide showing outstanding cutting efficiency when compared to that of an uncoated tool: maximal 940 mm/min infeed rates (app. 1 s to drill 17 mm) instead of 20 mm/min for the latter; absence of tool wear in contrast to a flank wear of about 50 μm in the uncoated tool after only 4 holes; hole edge integrity even at the highest infeed rates while grain decohesion at the hole edge takes place when using bare drill bits.     

Tribological behavior of magnetron sputtering CrMoN/MoS2 composite coatings

CrMoN composite coatings were deposited on the surface of the stainless steel by magnetron sputtering,then were treated by low temperature ion sulfuration.FESEM equipped with EDX was adopted to analyze the morphologies and compositions of the surface,cross-section and worn scar of the sulfuration layer.The valence states of the film surface were detected by XPS.The nano-hardness and nano-modulus of the layer were measured by a nano tester.The results of the friction and wear show that the CrMoN/MoS2 composite coating is a kind of ideal solid lubrication layer and possess an excellent antifriction and wear-resistance.     

Growth characteristics of MoS2 coatings prepared by unbalanced bipolar DC magnetron sputtering

MoS2 coatings were prepared by unbalanced bipolar DC magnetron sputtering under different argon pressures and for different deposition times, and the structure and morphology of MoS2 coatings were determined and observed respectively by X-ray diffractometry and scanning electron microscopy. The results show that at lower argon pressures of 0.15 Pa and 0.40 Pa, MoS2 coatings are formed with the （002） basal plane parallel to the surface, whereas the coating deposited at the argon pressure above 0.60 Pa has the （002） basal plane perpendicular to the surface. Two stages can be classified for the formation of MoS2 coating. At the initial stage of coating formation, the （002） basal plane with S-Mo-S layer structure grows on the substrate whatever the argon pressure is. And then the coating under 0.40 Pa argon pressure still grows with （002） laminate structure, but the coatings under 0.88 Pa and 1.60 Pa argon pressures turn to grow with the mixed basal and edge orientations. The morphology and structure of MoS2 coatings are highly related to their growth rate and the energy of sputtered particles.     

Growth of non-polar ZnO films on a-GaN/r-Al2O3 templates by radio-frequency magnetron sputtering

In this work, non-polar (1,1,?2,0) ZnO thin films have been grown on a-GaN/r-Al₂O₃ templates by radio-frequency magnetron sputtering. By varying the substrate temperature, the ZnO thin films were transformed from polycrystalline structure to epitaxial one on a-GaN/r-Al₂O₃ templates. High-quality (1,1,?2,0) ZnO epitaxial thin films were grown on the a-GaN/r-Al₂O₃ template at the optimized condition of 300 °C, which was confirmed by X-ray diffraction. The full width at half maximum (FWHM) of the (1,1,?2,0) ω-rocking curve of the a-plane ZnO films grown on the a-GaN/r-Al₂O₃ template was 0.51°, indicating a small mosaicity and a low dislocation density in the ZnO film grown on the a-GaN/r-Al₂O₃ template. Its surface roughness observed by atomic force microscopy was about 2.32 nm. Furthermore, the comparative investigation results show that the ZnO films grown on a-GaN/r-Al₂O₃ templates are more likely to form in the (1,1,?2,0)-orientation than those directly grown on r-sapphire.     

Tribological behavior and mechanism of NiCrBSi–Y2O3 composite coatings

The NiCrBSi–Y₂O₃ composite coatings were prepared on the surface of 45 carbon steel by plasma spray, the microstructure and tribological properties of the coatings were investigated. The results show that the NiCrBSi–Y₂O₃ composite coatings are mainly composed of γ-Ni, CrB, Cr₇C₃ and Y₂O₃. With addition of Y₂O₃, hard phases such as CrB, Cr₇C₃ emerge in composite coating, and the density of the composite coatings also increases. The NiCrBSi–0.5Y₂O₃ composite coating presents excellent tribological properties. Its friction coefficient is 0.175, which is about 37% of that of the pure NiCrBSi coating. The mass wear loss is 1.2 mg, which is reduced by 43% compared with the pure NiCrBSi coating. When the loads are 6–10 N, the NiCrBSi–0.5Y₂O₃ composite coating suffers from slight wear and the wear mechanisms are mainly adhesive wear accompany with slight micro-cutting wear and micro-fracture wear. As the load increases to 12 N, the wear mechanisms are adhesive wear and severe micro-cutting wear.     

Thermal conductivity and phase stability of plasma sprayed ZrO2–Y2O3–La2O3 coatings

Thermal conductivity and phase stability of La₂O₃,Y₂O₃ stabilized ZrO₂ plasma sprayed coatings were investigated. La₂O₃ was selected as a stabilizer because it had a significant effect on reducing densification of Y₂O₃ stabilized ZrO₂ (YSZ). The developed coating showed low thermal conductivity even after high temperature exposure due to its high resistance to sintering. However, phase stability and thermal cycle life of the coating decreased as the amount of La₂O₃ was increased. It was concluded that optimum amount of La₂O₃ addition was about 1 mol% to suppress sintering with little degradation of other properties.