Combined XRF‐SEM analysis of varnished pottery: the case of Syracuse and Adrano (Sicily) archaelogical finds

Micro‐destructive and non‐destructive X‐Ray fluorescence techniques and scanning electron microscopy coupled with energy‐dispersive spectrometry have been applied for the analysis of ten samples of Hellenistic black‐varnished pottery, coming from archaeological excavations in Syracuse and Adrano (South Italy, Sicily). Micro‐morphological and compositional investigations, together with statistical data processing, have shown several differences among the varnishes of the specimen found in the two sites. In particular, Syracuse varnishes are characterised by a more homogeneous composition and well‐defined raw materials, whereas Adrano samples show a higher variability, probably linked to the use of different raw materials and the poorer quality of the varnish as well. The obtained results attest that, as Syracuse black pottery is concerned, the production technique is at an advanced level, whereas Adrano manufacture seems to be less specialised. Copyright © 2012 John Wiley & Sons, Ltd.     

银薄膜对光学基底表面粗糙度及光散射的影响

为了研究金属银薄膜与光学基底表面粗糙度和光散射的关系,提出了通过对光学薄膜矢量散射公式积分来获得界面粗糙度完全相关模型和完全非相关模型下其表面的总反射散射的方法.理论计算了光学基底上两种模型在不同厚度银膜下的总反射散射和双向反射分布函数.结果表明,当沉积在光学基底上的银薄膜的厚度大于80 nm后,两种模型下计算的银薄膜的表面总反射散射都等于基底的总积分散射,银薄膜能较好地复现出基底的粗糙度轮廓.实验研究表明为了复现基底的粗糙度,银薄膜的最佳厚度应在80~160 nm之间.     

Investigation of interface roughness cross-correlation properties of optical thin films from total scattering losses

The interface roughness and interface roughness cross-correlation properties affect the scattering losses of high-quality optical thin films. In this paper, the theoretical models of light scattering induced by surface and interface roughness of optical thin films are concisely presented. Furthermore, influence of interface roughness cross-correlation properties to light scattering is analyzed by total scattering losses. Moreover, single-layer TiO₂ thin film thickness, substrate roughness of K9 glass and ion beam assisted deposition (IBAD) technique effect on interface roughness cross-correlation properties are studied by experiments, respectively. A 17-layer dielectric quarter-wave high reflection multilayer is analyzed by total scattering losses. The results show that the interface roughness cross-correlation properties depend on TiO₂ thin film thickness, substrate roughness and deposition technique. The interface roughness cross-correlation properties decrease with the increase of film thickness or the decrease of substrates roughness. Furthermore, ion beam assisted deposition technique can increase the interface roughness cross-correlation properties of optical thin films. The measured total scattering losses of 17-layer dielectric quarter-wave high reflection multilayer deposited with IBAD indicate that completely correlated interface model can be observed, when substrate roughness is about 2.84 nm.     

Influence of superalloy substrate roughness on adhesion and oxidation behavior of magnetron-sputtered NiCoCrAlY coatings

The present study has been conducted in order to determine the influence of superalloy substrate roughness on adhesion and oxidation behavior of magnetron-sputtered NiCoCrAlY coatings. Six types of coating samples with different substrate roughness were tested. The surface roughness and real surface area of both the substrates and coatings were studied by atomic force microscopy (AFM) techniques. The scratch tests performed at progressive loads were employed to evaluate the adhesion of the coatings. Cyclic oxidation tests were performed at 1100 °C in air for 50 cycles, each cycle consisting of 1 h heating in the tube furnace followed by 15 min cooling in the open air. The AFM measurements exhibit that the surface roughness of the sputtered NiCoCrAlY coating increases with the increasing of the superalloy substrate roughness. The NiCoCrAlY coatings present slightly lower roughness than the corresponding superalloy substrate. The scratch adhesion tests indicate that the coatings on substrates with a smoother surface possess better adhesion than on those with a rougher surface. Both the real surface area and oxidation weight gain of the coatings decrease with the decreasing of the superalloy substrate roughness. The NiCoCrAlY coating sputtered on the superalloy substrate with lower roughness provides relatively higher antioxidant protection than that provided by the coating with rougher substrate.     

银薄膜对光学基底表面粗糙度及光散射的影响

为了研究金属银薄膜与光学基底表面粗糙度和光散射的关系,提出了通过对光学薄膜矢量散射公式积分来获得界面粗糙度完全相关模型和完全非相关模型下其表面的总反射散射的方法．理论计算了光学基底上两种模型在不同厚度银膜下的总反射散射和双向反射分布函数．结果表明,当沉积在光学基底上的银薄膜的厚度大于80nm后．两种模型下计算的银薄膜的表面总反射散射都等于基底的总积分散射,银薄膜能较好地复现出基底的粗糙度轮廓．实验研究表明为了复现基底的粗糙度,银薄膜的最佳厚度应在80～160nm之间．     

Enhanced retroreflectance effects in the reflection of light from randomly rough surfaces

A review is made of theoretical and experimental work on retroreflection enhancements in the diffuse component of light elastically reflected from randomly rough surfaces. These effects are seen as a narrow peak in the angular distribution of the intensity of diffusely reflected light which is centered about the direction for reflected light motion antiparallel to the original incident beam. This peak is observed in the scattering of light from many different types of rough surfaces and has been studied in fields as diverse as solid state physics, astronomy, geophysics, meterology and radar. Work covering all of these fields will be presented in this review.

Retroreflection enhancements arise both from shadow casting properties of surface irregularities and from the phase coherence of retroreflected light. These mechanisms can act to create retroreflection enhancements from rough surfaces of dielectric and/or metallic compositions and of surface disorders characterizable on length scales which are large, comparable to or small compared to the wavelength of the scattered light.

Specific discussions will be presented of three types of enhanced retroreflectance: (1) A treatment of the optical glory and Heiligenschein phenomena which are concerned with the meterological and geophysical study of light reflected from clouds and terraine will be given. (2) The theory of the opposition effect, encountered in astronomy as an enhanced retroreflection in the light scattered from atmosphereless planets and space debris, will be used to provide a theoretical basis to understand shadowing effects. (3) A recently discovered phenomenon of enhanced retroreflection from weakly rough metallic mirrors, associated with the Anderson localization of surface waves, is also presented. This last phenomenon and its relationship to the study of the Anderson localization of surface waves will be emphasized throughout our discussions.

Similar enhancement effects in the scattering of acoustic waves from rough surfaces and a brief outline of some recent work on optical backscattering enhancements due to the Anderson localization of bulk polariton modes, is also presented.     

Determination of surface roughness from light scattering measurements

We have measured the angular dependence of the p- and s-pollarized light scattered on films, which are supported by fine polished Suprasil substrates. To study the roughness of the surface we have varied the evaporation process and the thickness of the silver film. We quantitatively determine the roughness structure by using a non scalar scattering theory. The roughness structure is found in good agreement with measurements on the same films using ATR-techniques.     

透明基底表面双向反射分布函数及粗糙度特性研究

采用双向反射分布函数定量分析透明基底表面粗糙度,考虑到透明基底第二个界面的影响,从不透明基底双向反射分布函数入手,推导了实际测量的透明基底表面双向反射分布函数的表达式.依据此理论提出了通过分别测量两个表面的散射强度来联立求解透明基底实际表面反射分布函数和表面粗糙度谱的新方法.并将此结果与用原子力显微镜测量所获得的结果进行了比较,两者吻合较好.     

Nanoscale surface roughness characterization by full field polarized light-scattering

Characterizing surface roughness in nanoscale nondestructively is an urgent need for semiconductor and wafer manufacturing industries. To meet the need, an optical scatter instrument in bidirectional ellipsometry has been developed for characterizing nanoscale surface roughness, in particular, on the wafers after chemical-mechanical polishing. The polarized angular dependence of out-of-plane light-scattering from nanoscale surface roughness is analyzed and characterized. These analysis and characterization results show strong correlations of surface roughness and angular dependence of bidirectional ellipsometric parameters for full field light-scattering. The experimental findings prove good agreement with theoretical predictions for different surface roughnesses. As a result, the nanoscale surface roughness can be accurately measured and characterized by the angular dependence and the polarization of light scattered from surface.     

Evaluation of adhesion between glass/epoxy composite substrate and copper foil for printed circuit board applications

Adhesion between glass/epoxy composite substrate and copper foil was evaluated by 90° peeling test. Effect of fracture behavior and the peel strength on copper foil style was experimentally investigated using copper foils with various surface roughness. As mechanical anchoring effect increases with increased surface roughness, the surface roughness increased the surface roughness of copper foil strongly affected the peeling strength and local load variation during the test. The fracture behavior was characterized by secondary electron image and reflective electron image techniques of scanning electron microscopy (SEM). All of the specimens were found to fracture at the anchor points formed in the resin layer on the surface of the substrate. The experimental results were correlated to a formulation based on the theory of beams on elastic foundation, which is presented for predicting the adhesive strength in the adherend- adhesive system. In order to apply this formulation to a no adhesive system, such as FR-4/copper foil, an analytical model was proposed. In this model, a mixture phase of the copper with the surface resin in the substrate was regarded as the adhesive. The calculated results were in relatively good agreement with the experimental results. It was confirmed that the analysis model and evaluation method is useful to predict the peel strength due to the mechanical anchoring effect.     

Effect of substrate morphology on the roughness evolution of ultra thin DLC films

The effect of substrate roughness on growth of ultra thin diamond-like carbon (DLC) films has been studied. The ultra thin DLC films have been deposited on silicon substrates with initial surface roughness of 0.15, 0.46 and 1.08 nm using a filted cathodic vacuum arc (FCVA) system. The films were characterized by Raman spectroscope, transmission electron microscope (TEM) and atomic force microscopy (AFM) to investigate the evolution of the surface roughness as a function of the film thickness. The experimental results show that the evolution of the surface morphology in an atomic scale depends on the initial surface morphology of the silicon substrate. For smooth silicon substrate (initial surface roughness of 0.15 nm), the surface roughness decreased with DLC thickness. However, for silicon substrate with initial surface roughness of 0.46 and 1.08 nm, the film surface roughness decreased first and then increased to a maximum and subsequently decreased again. The preferred growth of the valley and the island growth of DLC were employed to interpret the influence of substrate morphology on the evolution of DLC film roughness.     

On the control of thin film growth by angular reflectometry near the brewster angle

The method of angular reflectometry is used to analyze the formation dynamics of layered structures on transparent substrates. This method is highly sensitive to changes in the parameters of a film structure at the early stage of formation thereof. It is based on the angular dependence of the reflected signal intensity near the Brewster angle and is almost independent of the state of the measuring facility. Experimental data obtained for multiferroic thin films on an isotropic crystalline Al₂O₃(001) substrate are presented. The films on the Al₂O₃(001) substrate are obtained by sputtering a Bi_0.95Nd_0.05FeO₃ target for 5–600 s in an rf glow discharge initiated in oxygen.     

A step forward in the study of the electroerosion by optical methods

This work develops two theoretical models of surfaces to explain the behavior of the light scattered by samples that suffers some alteration.

In a first model, it is evaluated the mean intensity scattered by the sample, analyzing the different curves obtained as function of the eroded/total surface ratio. The theoretical results are compared with those obtained experimentally. It can be seen that there exists a strong relation between the electroerosion level and the light scattered by the sample.

A second model analyzes a surface with random changes in its roughness. A translucent surface with its roughness changing in a controlled way is studied. Then, the correlation coefficient variation as function of the roughness variation is determined by the transmission speckle correlation method. The obtained experimental values are compared with those obtained with this model.

In summary, it can be shown that the first- and second-order statistics properties of the transmitted or reflected light by a sample with a variable topography can be taken account as a parameter to analyze these morphologic changes.     

二氧化锆薄膜表面粗糙度的研究

采用电子束蒸发工艺,利用泰勒霍普森相关相干表面轮廓粗糙度仪,研究了不同基底粗糙度、不同二氧化锆薄膜厚度以及不同的离子束辅助能量下所沉积的二氧化锆薄膜的表面粗糙度。结果表明：随着基底表面粗糙度的增加,二氧化锆薄膜表面粗糙度呈现出先缓慢增加,当基底的粗糙度大于10nm后呈现快速增加的趋势;随着二氧化锆薄膜厚度的增加,其表面均方根粗糙度（RMS）先减小后增大;随着辅助沉积离子能量的增加,其表面粗糙度呈现出先减小后增加的趋势。     

An application of the optics of oil films to the study of engineering surfaces

The flow of an oil film draining down a rough surface is studied, to show that as a result of the surface tension, only the long wave components of the roughness give rise to corrugation of the film surface. The oil thus serves two purposes, to provide a reflecting surface and to provide a low-pass spatial filter for the surface roughness spectrum. Observation in out-of-focus reflected light shows the film corrugations clearly, thus giving selective information about the rough surface underneath.     

蓝宝石基片的处理方法对ZnO薄膜生长行为的影响

采用反应射频磁控溅射方法,在经过不同方法处理的蓝宝石基片上,在同一条件下沉积了ZnO薄膜.利用原子力显微镜、X射线衍射、反射式高能电子衍射等分析技术,对基片和薄膜的结构、表面形貌进行了系统表征.研究结果显示,不同退火条件下的蓝宝石基片表面结构之间没有本质的差异,均为α-Al₂O₃ (001)晶面,但基片表面形貌的变化较大.在不同方法处理的蓝宝石基片上生长的ZnO薄膜均具有高c轴取向的织构特征,但薄膜的表面形貌差异较大.基片经真空退火处 关键词： ZnO薄膜 反应磁控溅射 基片处理 形貌分析     

Roughness of pigment coatings and its influence on gloss

A robust method is used for analyzing roughness at a wide range of lateral length scales. The method is based on two-point correlation where both the amplitude and lateral spacing of surface heights are considered when determining the roughness. Atomic force microcopy and confocal optical microscopy images were captured for a set of pigment-coated samples. The effects of sampling interval, image size and filtering on surface roughness were studied. Isotropy and periodicity of roughness were determined by analyzing the angular distribution of the correlation length (T) and the autocorrelation function (ACF). A clear dependence of root mean square (RMS) roughness (σ) on T was established for randomly distributed surfaces. By taking into account the σ-T dependence it was possible to obtain σ for various length scales for each sample and thus attaining the most relevant σ for a certain surface function, which in this study was specular reflection of light (gloss). The roughness analysis showed that a small amount of DPP coating was sufficient to completely cover and change the surface of the substrate, while kaolin coatings gave a different response.     

Enhanced backscattering and transmission of light from random surfaces on semi-infinite substrates and thin films

The enhanced backscattering of light from a random surface is manifested by a well defined peak in the retro-reflection direction in the angular distribution of the intensity of the incoherent component of the light scattered from such a surface. In this paper we present several new theoretical and experimental results bearing on the conditions under which enhanced backscattering occurs, and the way in which this phenomenon depends on the nature of the random surface roughness, both in the case that the random surface bounds a semi-infinite scattering medium and in the case that it bounds a film, either free-standing or on a reflecting substrate. In addition, we present new results on the transmission of light through thin metallic films bounded by random surfaces, which display the phenomenon of enhanced transmission, namely a well defined peak in the antispecular direction in the angular distribution of the intensity of the incoherent component of the light transmitted through such films.     

Qualification of superpolished substrates for laser-gyro by surface integrated scatter measurement

<正>Integrated scatterometer for qualification of superpolished substrates for laser-gyro by surface scatter loss measurement is constructed.Different from the qualification of substrate by surface roughness,the scatterometer measures the forward surface scatter loss to check whether the mirror made of the substrate will be suitable for the required laser-gyro lock-in specification.The scatterometer utilizes convex lens instead of integrating sphere to collect scatter light.Special sample support and baffle are designed to block unwanted light.The result of stability test is given,which is about 0.4%over 10 h.