Effect of interfacial roughness on dewetting behavior of polystyrene/poly(methyl methacrylate) bilayer film

The dewetting behavior of polystyrene (PS) film on poly(methyl methacrylate) (PMMA) sublayer was investigated by changing the short-range roughness of the PMMA sublayer systemically. When the bilayer film was heated to the temperature above both Tgs, the protuberances formed in both layers to reduce the system energy. By tracing the dewetting process of the PS up-layer, the dewetting velocity was found to increase with the roughness of the sublayer.

Fabrication of Iron Oxide Core/Gold Shell Submicrometer Spheres with Nanoscale Surface Roughness for Efficient Surface-Enhanced Raman Scattering

A method to synthesize Fe3O4 core/Au shell submicrometer structures with very rough surfaces on the nanoscale is reported. The Fe3O4 particles were first modified with uniform polymers through the layer-by-layer technique and then adsorbed a lot of gold nanoseeds for further Au shell formation. The shell was composed of a large number of irregular nanoscale An particles arranged randomly, and there were well-defined boundaries between these Au nanoparticles. The Fe3O4 core/Au shell particles showed strong plasmon resonance absorption in the near-infrared range, and can be separated quickly from solution by an external magnet.

Fractal roughness characterization of super-ground Mn-Zn ferrite single crystals

The surface of superground Mn-Zn ferrite single crystal may be identified as a self-affine fractal in the stochastic sense. The rms roughness increased as a power of the scale from 10(2) nm to 10(6) nm with the roughness exponent alpha = 0.17 +/- 0.04, and 0.11 +/- 0.06, for grinding feed rate of 15 and 10 mu m/rev, respectively. The scaling behavior coincided with the theory prediction well used for growing self-affine surfaces in the interested region for magnetic heads performance. The rms roughnesses increased with increase in the feed rate, implying that the feed rate is a crucial grinding parameter affecting the supersmooth surface roughness in the machining process.

Surface roughness characterization of soft x-ray multilayer films on the nanometer scale

The soft x-ray reflectivity of multilayer films is affected by the surface roughness on the transverse nanometer scale. Scanning tunneling microscopy (STM) is an ideal instrument for providing high-lateral-resolution roughness measurements for soft x-ray multilayer films that cannot be obtained with other types of instruments on the transverse nanometer scale. The surface roughnesses of Mo/Si, Mo/C, and W/Si soft x-ray multilayer films prepared by an ion-beam-sputtering technique were measured with a STM on the vertical and transverse attributes. The film roughnesses and average spatial wavelengths added to the substrates depend on the multilayer film fabrication conditions, i.e., material combinations, number of layers, and individual layer thickness. These were estimated to lead to a loss of specular reflectivity and variations of the soft x-ray scattering angle distribution. This method points the way to further studies of soft x-ray multilayer film functional properties and can be used as basic guidance for selecting the best coating conditions in the fabrications of soft x-ray multilayer films. (C) 1996 American Vacuum Society.

Resolution deterioration in emission electron microscopy due to object roughness

In the present paper a general analytic expression has been obtained and confirmed by a computer simulation which links the surface roughness of an object under study in an emission electron microscope and it's resolution. A quantitative derivation was made for the model case when there is a step on the object surface. It was shown that the resolution is deteriorated asymmetrically relative to the step. The effect sets a practical limit to the ultimate lateral resolution obtainable in an emission electron microscope.

Towards Extracting Absolute Roughness From Underground Mine Drift Profile Data

The purpose of this paper is to demonstrate a technique to utilize underground mine drift profile data for estimating absolute roughness of an underground mine drift in order to implement the Darcy-Weisbach equation for mine ventilation calculations. This technique could provide mine ventilation engineers with more accurate information upon which they might base their ventilation systems designs. This paper presents preliminary work suggesting that it is possible to estimate the absolute roughness of drift-like tunnels by analyzing profile data (e.g., collected using a scanning laser rangefinder). The absolute roughness is then used to estimate the friction factor employed in the Darcy-Weisbach equation. The presented technique is based on an analysis of the spectral characteristics of profile ranges. Simulations based on real mine data are provided to illustrate the potential viability of this method. It is shown that mining drift roughness profiles appear similar to Gaussian profiles