Copper roughness factors

This conclusion was additionally confirmed by Palczewska and Janko (67) in separate experiments, where under the same conditions nickel-copper alloy films rich in nickel (and nickel films as well) were transformed into their respective hydride phases, which were proved by X-ray diffraction. The additional argument in favor of the transformation of the metal film into hydride in the side-arm of the Smith-Linnett apparatus consists of the observed increase of the roughness factor ( 70%) of the film and the decrease of its crystallite size ( 30%) after coming back from low to high temperatures for desorbing hydrogen. The effect is quite similar to that observed by Scholten and Konvalinka (9) for their palladium catalyst samples undergoing the (a — j8) -phase transformation. 

Oxidation-reduction cycle. A sample of freshly electropolished polycrystalline copper with an initial roughness factor of almost unity was treated by an oxidation-reduction cycle in which an oxide film effective thickness of 200 A. was formed and removed. This was done (1) to illustrate the usefulness of the adsorption technique for defining the... 

The results of studies of copper surfaces by low-temperature adsorption isotherms may be summarized as follows. True surface areas of metallic specimens as small as 10 sq. cm. can be derived with a precision of 6% from low-temperature adsorption isotherms using vacuum microbalance techniques. This method is of special value in determining the average thickness of corrosion films formed by the reaction of gases or liquids with solids. The effect of progressive oxidation of a rough polycrystalline metal surface is to decrease the surface area to a point where the roughness factor approaches unity. 

The observed roughness factors (ratio of true to geometric surface) of the surfaces employed in this study varied from 1.2 to 1.4 (Table IV). This checked with electron microscope pictures of alumina and silica replicas from electropolished single crystal copper surfaces. It is unlikely that the surface areas determined by the Brunauer-Emmett-Teller analysis are too high by 50% or even by 25%, because in several cases this would lead to a roughness factor of less than unity. 

Sosnovsky s data are plotted by us in Fig. 7. In the calculation of the pre-exponential factor we assumed that the roughness factor of the surfaces is of the order of unity this is in accordance with Sosnovsky s observation that under all conditions of pretreatment the surfaces remained perfectly smooth. From Fig. 7 it is seen that, dependent on the surface orientation and the energy of the bombarding ions, the activation energies are found to vary from 12 to 35 kcal/mole. However, as was also found by Crocker and Robertson (37) in the case of copper, the change... 

The soft high clay taUing from a copper concentrator develops a Bingham viscosity of 400 mPa s at a weight concentration of 45% as well as a yield stress of 5 Pa. The slurry density is 1350 kg/m. The taUings flow rate is 1600 m /hr. If the maximum allowed slope is 1.5%, determine the suitable size for a half-full smooth HDPE pipe (i.e., ignore roughness factor). 

When organic molecules are close to (within a few A) or adsorbed on rough surfaces of certain metals, such as silver, copper, or gold, a very large enhancement of their Raman spectra (by a factor of ca. 106-108) may be observed. 

Note Copper traces can t provide a very low inductance if they are long, however wide they may be. We must remember that though halving the length of any trace does roughly halve its inductance, we have to increase the width of a trace by a factor of 8 to 10 to halve its inductance (see Chapter 6). 

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