PET基纳米Ag薄膜形貌与导电及电磁屏蔽性能的分形表征

采用磁控溅射法在PET非织造布上制备了不同厚度的纳米结构Ag薄膜,用高度相关函数法对薄膜的原子力显微镜(AFM)图像进行分形维计算,用AFM分析不同厚度纳米结构Ag薄膜形貌及粒径的变化;用网络测试仪测试了不同厚度样品的电磁屏蔽效能。结果表明,随着薄膜厚度的增加,薄膜表面质量提高,分形维增大;电磁屏蔽效能也随分形维的增大而增加。可以认为,分形维能有效地表征薄膜的表面形貌,分形维与导电及屏蔽效能存在明显的对应关系,并可以用分形维优化磁控溅射的工艺条件。     

Ti种子层对Cu薄膜的微观织构和表面形貌的影响

用磁控溅射法制备无种子层的Cu薄膜和加入Ti作为种子层的Ti/Cu薄膜,用电子背散射衍射技术(EBSD)研究了无种子层的Cu薄膜及有Ti种子层的Ti/Cu薄膜的微观织构,并用原子力显微镜(AFM)观察了两种薄膜的表面形貌。结果表明,加入Ti作为种子层增强了Cu薄膜的{111}纤维织构,对薄膜生长有很好的外延作用。同时,加入Ti种子层可降低退火处理后薄膜内退火孪晶的产生几率,但是在退火过程中使孔洞出现。     

溅射超薄Au膜表面形貌的分形表征

采用直流磁控溅射技术制备超薄Au膜,用原子力显微镜观察薄膜的表面形貌。功率谱密度计算结果显示,随着溅射时间增加,高频段曲线拟合直线的斜率增大,相应的分形维数从2.579减小到2.500;而低频段曲线拟合直线的斜率减小,相应的分形维数由2.607增大到2.819,薄膜表面形貌存在多尺度行为。多重分形谱结果表明,随着溅射时间的增加,分形谱宽Δα从0.051增大到0.118,说明薄膜表面高度分布范围愈来愈宽,表面粗糙度愈来愈大,与rms研究结果一致。样品的Δf均0,说明样品表面最高峰位的数目均多于最低谷位的数目。     

Ti(Ta)O2薄膜的表面形貌对血管内皮细胞生长量影响的研究

采用磁控溅射合成不同Ta含量的系列Ti(Ta)O2薄膜.利用扫描电子显微镜(SEM)、原子力显微镜(AFM)对薄膜的表面形貌进行表征.并对薄膜表面进行人脐静脉内皮细胞(HUVEC)种植试验以评价薄膜材料的表面形貌对细胞组织相容性的影响.结果表明,细胞在不同Ta含量的Ti(Ta)O2薄膜表面因表面形貌的不同具有明显不同的粘附、增殖和生长行为.薄膜表面适当的粗糙度有利于细胞的贴附、生长和增殖.该研究指出,通过控制材料表面改性层的特征,可改善其表面细胞生物学行为,并可提高薄膜材料表面生物相容性.     

TiO_2/SiO_2非晶复合薄膜的超亲水性能研究

自制靶材,采用射频磁控溅射法制备超亲水TiO_2/SiO_2非晶复合薄膜,用XRD、AFM、XPS、液滴形状分析仪等方法进行表征。研究了溅射气氛、射频功率以及溅射时间对薄膜亲水性能的影响,并探讨了TiO_2/SiO_2非晶复合薄膜的超亲水机理。结果表明,Ti、Si元素进入薄膜晶格,在TiO_2/SiO_2薄膜界面形成Si—O—Ti键,约为22.4%;Si—O—Ti键的形成增加薄膜表面酸性,提高薄膜表面羟基含量,使薄膜具有超亲水特性。     

铜薄膜在100℃～400℃下氧化行为的微观表征

本文研究了在100℃～400℃下溅射制备的40nm铜薄膜的氧化行为。利用原子力显微镜（AFM）观察了铜薄膜氧化前期的微观形貌，并利用X射线衍射（XRD）和能量分散X射线谱（EDX）分析了其晶相结构和成份。随着温度的升高，铜薄膜氧化速率明显加快。在100℃下，Cu薄膜表面生成岛状非晶氧化物，温度升高至200℃后，生成Cu2O相的同时Cu薄膜表面产生重构现象，呈现疏松的网状结构。300℃和400℃下Cu薄膜几乎全部氧化，分别形成均匀分布的Cu2O和CuO晶粒。结果表明，利用AFM和XRD能灵敏地跟踪纳米尺度Cu薄膜的氧化过程。     

功率和温度对a-C:F:H膜表面形貌和结构的影响

分析薄膜的表面形貌对其生长机理和光学性质研究有着十分重要的作用。本文使用CF4和CH4为源气体，利用射频等离子体增强化学气相沉积（RF—PECVD）法在不同射频功率和沉积温度下制备了掺氟氢化无定形碳（a—C：F：H）薄膜，并在N2气氛中进行了不同温度的退火处理。用原子力显微镜（AFM）和扫描电子显微镜（SEM）观察了薄膜表面形貌，发现低功率下沉积的薄膜表面均匀性好、缺陷少；在低温下沉积的薄膜表面光滑，而高温下粗糙；真空低温退火可使薄膜表面形貌得到改善，但薄膜内空洞增加，退火温度过高，薄膜的结构发生变化，且在薄膜表面发生皲裂现象。用Raman光谱对薄膜内的结构变化进行了进一步的分析。     

SiCN扩散阻挡层薄膜的制备及特性研究

采用磁控溅射法在单晶硅衬底上制备了SiCN及Cu/SiCN薄膜,并对试样进行了退火处理.利用原子力显微镜(AFM)、X射线衍射(XRD)、四探针测试仪(FPP)研究了SiCN薄膜的表面形貌、物相结构及在Cu/SiCN/Si结构中SiCN薄膜对铜与硅的阻挡性能.结果表明,沉积态SiCN薄膜为无定型的非晶结构,晶化温度在1000℃以上;SiCN薄膜作为Cu的扩散阻挡层有较好的热稳定性及阻挡性,阻挡失效温度在600℃左右.     

磁控溅射玄武岩纤维基纳米Cu薄膜微观结构分析的研究

采用直流磁控溅射法在玄武岩纤维表面沉积纳米Cu薄膜,工作气体为氩气,利用原子力显微镜(AFM)和扫描电子显微镜(SEM)观察Cu薄膜在纤维表面的微观结构,并较为系统地分析了磁控溅射工艺参数对Cu薄膜表面颗粒尺寸、表面粗糙度等的影响,采用X射线能谱仪(EDX)分析了溅射前后表面各元素的含量。结果表明:随着溅射功率的增大,溅射时间的延长其表面颗粒的团聚增强;溅射压强增大会导致表面粗糙度增大;基底温度的升高会导致Cu粒子热迁移现象,表面粗糙度增大,但对表面裂纹的产生有一定的改善,并利用AFM测试了裂纹的宽度和深度。     

Sol-gel法制备NiZnCu铁氧体性能的研究

采用溶胶-凝胶自燃法制备了Ni0.4Zn0.4Cu0.2Fe2O4铁氧体,使用HP4191A阻抗分析仪测试了材料高频磁谱;结合快速热处理(RTP)工艺制备了Ni0.4Zn0.4Cu0.2Fe2O4磁性薄膜,使用AFM、XRD、AGM系统地研究了制备工艺对薄膜样品表面形貌、晶相结构和准静态磁性的影响。测试结果表明:Ni0.4Zn0.4Cu0.2Fe2O4可适用于射频领域,截止频率fr在1GHz以上,1GHz处起始磁导率μ′=5.3,μ″=3.45;sol-gel法制备磁性薄膜最佳晶化温度为600℃左右,在此温度下制备的薄膜晶粒大小为13nm左右,饱和磁化强度Ms=2.29×105A/m,矫顽力Hc=1.24×103A/m。     

PAA与PBTCA对CaCO3显微结构的影响

利用扫描电镜（SEM）和原子力显微镜（AFM）研究了分散剂PAA与PBTCA对CaCO3显微结构的影响，结果表明，与PAA相比，PBTCA对CaCO3的沉积形貌具有更大的影响，SEM表明，在两种分散剂存在下，沉积物的形貌皆发生了变化，随着阻滞剂影响增大，沉积物晶型畸变程度随之严重，沉积物的形貌的分维值也随之增大，XRD分析表明，随着阻滞影响增大，CaCO3晶相中球霰石的含量增大，在分散剂存在下，热力学上属亚稳态的文石和球霰石从动力学上被稳定住了，AFM研究表明，随着阻滞影响增大，CaCO3晶体表面上台阶间距变大，同时，发现了CaCO3晶体表面台阶的聚并现象并进行了讨论。     

PAA与PBTCA对CaCO3显微结构的影响

利用扫描电镜(ＳＥＭ)和原子力显微镜(ＡＦＭ)研究了分散剂ＰＡＡ与ＰＢＴＣＡ对ＣａＣＯ _３显微结构的影响．结果表明,与ＰＡＡ相比,ＰＢＴＣＡ对ＣａＣＯ_３的沉积形貌具有更大的影响．ＳＥＭ表明,在两种分散剂的存在下,沉积物的形貌皆发生了变化,随着阻滞影响增大,沉积物晶型畸变程度随之严重,沉积物形貌的分维值也随之增大．ＸＲＤ分析表明,随着阻滞影响增大,ＣａＣＯ_３晶相中球霰石的含量增大．在分散剂存在下,热力学上属亚稳态的文石和球霰石从动力学上被稳定住了．ＡＦＭ研究表明,随着阻滞影响增大,ＣａＣＯ_３晶体表面上台阶间距变大．同时,发现了ＣａＣＯ_３晶体表面台阶的聚并现象并进行了讨论．     

ABS塑料断面形貌特征及分形分析

分析测字了ＡＢＳ塑料冲击断面的形貌特征及对应的分形维数值，结果表明，不同断面表貌特征所对应的分形维数测量值不同，ＡＢＳ无缺口冲强度随满足自相似原理的形貌特征对应的分形维数测量值增大而线性增高，不满足自相似原理的形貌特征所对应的分形维数测量值量宏观冲击强度间无明显关系，但其大小仍合理表征了相应尺度范围内的形貌的特征变化。     

Fractal dimension of the surface of porous ceramic materials

The fractal dimension D of the surface of porous ceramic materials has been determined. The dependence of D on the total porous space volume exhibits two bending points, which reflects a change in the character of porosity on the passage from isolated pores to connected pore clusters and to very large pores with smooth boundaries. This behavior reveals a correlation between the fractal dimension and some well-known features in the properties of porous solids.     

A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges

PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar–O₂ atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (< 5 at.%), in the form of TiO₂ on the PET treated surface. The TiO₂ is probably distributed as an island-like distribution covering the PET surface. Presence of Cu and Ti oxide constituents on the treated PET is beneficial in aiding the adhesion but alone (i.e. without oxygen plasma activation) is not enough to provide very high levels of hydrophilicity as is clear from sessile drop water contact angle measurements on aged samples. Exposure to the plasma treatments leads to a small amount of roughening of the substrate surface, but the average surface roughness in all cases is below 2.5 nm. The PET structure at the interface with a coating is mostly or wholly preserved. The oxygen plasma treatment, metal oxide deposition and surface roughening resulting from the HIPIMS and p-DC treatments will promote adhesion to any subsequent thin film that is deposited immediately following the plasma treatment.     

Fractal processing of AFM images of rough ZnO films

Fractal image processing has been applied to characterize the surface roughness of ZnO films as measured by atomic force microscopy. The simple fractal analysis suggests that the fractal dimension D can be used to describe the change of the whole grain morphology along the growth direction. Multifractal analysis shows that the scaling range is close to three orders of magnitude, which is larger than that of a simple fractal and most empirical fractals. The width of the multifractal spectrum can be used to characterize the roughness of the film surface quantitatively and the shape of multifractal spectrum can describe the ratio between the number of the lowest valleys and the highest peaks statistically.     

爆破振动信号时频特征的三维分形特性研究

为进一步研究爆破振动信号能量特征,基于小波包变换方法对爆破振动信号时频能量特征进行分析。在二维矩形盒维数模型的基础上建立了计算三维曲面分形盒维数模型,并计算得到实测爆破振动信号时频能量谱的三维分形盒维数D3d=2.148 8。该分形维数满足空间分形条件2D3d3,验证了爆破振动信号时频能量谱具有三维分形特征。经研究三维分形曲面盒维数D3d与其剖面二维分形盒维数D2d之间的数值关系,表明计算空间分形曲面分维数的常规假设D3d=D2d+1并非严格成立。研究表明,所提出的长方体覆盖空间曲面的分形维数计算方法可行、有效,为进一步研究爆破振动信号特征、控制爆破地震效应提供了新的研究思路。     

Fractal character of in situ heat treated metal-compound semiconductor contacts

The heat treatment of metallized (Au) compound semiconductors (InP) was studied by in situ scanning electron microscopy combined with mass spectrometry. Correlation was found between the change in the surface morphology and the volatile component loss caused by the material interactions taking place during the heat treatment. Our experiments proved that the surface morphology can be characterized by its fractal dimension at the maximum value of the volatile component loss. In this paper the dependence of the fractal dimension of the surface pattern on the heat treatment temperature (in a given temperature range), on the volatile component loss and on metal thickness is described. Changes of the surface morphology on the analyzed samples begin at different temperatures. The evaluated patterns were created describing contour lines of the metal islands on the surface. This island formation known as balling-up phenomenon is due to the heating up of the samples. In the case of the 10 and 30 nm Au/InP(100) samples the fractal behavior appeared nearly at the same temperature (470^∘C α 490^∘C). The examined thick Au(85 nm)/InP(100) contact showed a fractal character at a lower (385^∘C) temperature. Although fractal dimension values could be obtained in a rather wide temperature range the surface had a real fractal character at only those temperatures where volatile component loss took place.     

Pore morphology in pressurized lignite coal: A small angle x-ray scattering investigation

The morphological changes in lignite coal at two different pressures, using small angle x-ray scattering, have been investigated. All the scattering profiles are interpreted in terms of surface fractal morphology. It is observed that the surface fractal dimension does not change appreciably under the experimental pressure range, while the volume of micro-cracks and inter-particle pore space is reduced with increasing pressure. By and large, the constant value of the surface fractal dimension of all the specimens, as calculated from the scattering profiles, indicates that the roughness on the pore coal interface remains almost unaffected under the experimental pressure range. The validity of single scattering approximation for this experiment has also been confirmed by the observation of the identical nature of the small angle scattering profiles with respect to change of wave lengths, namely, 0.154 nm. (Cu K) and 0.072 nm (Mo K), of the probing radiation.