Ellipsometric method

Studies have been made on the rate of growth of oxide films on different crystal faces of a metal using ellipsometric methods. The rate was indeed different for (100), (101), (110), and (311) faces of copper [162] moreover, the film on a (311) surface was anisotropic in that its apparent thickness varied with the angle of rotation about the film normal. 

Met. = Method. C = chronocoulometry, CC = corrosion current method, EC = Electrocapillary method, EL = Ellipsometric method, IR = Infrared spectroscopic method, CV = cychc voltammetry, RT = Radiotracer method, T = Tensammetry, TF = Thin film resistance, WL = weight loss method. When a combination of methods was used aU methods are listed separated by slashes. See also list of symbols. 

In [67], an optoelectrochemical method (OEM) or a combination of electrochemical and ellipsometric methods, was developed for unambiguous evaluation of surface state and electrocatalytic properties of smooth standardized and modified... 

Kim, et al., ( ) have utilized radioiodinated (I proteins to measure adsorption of individual proteins and protein mixtures on LTI carbon surfaces. Their results indicate a very rapid adsorption of albumin onto the LTI carbon surface, consistent with Kim s model of blood interactions via a platelet-adhesion mechanism (.8). Microcalorimetric and electrophoretic mobility studies of protein adsorption on LTI carbon surfaces have been done by Chiu, et al., ( 5). The extension of the adsorbed protein layers have been directly measured by Fenstermaker, et al., ( ) and Stromberg et al., 7) at NBS using ellipsometric methods. 

PCL with CTBN or CTBR APS Ellipsometric methods. A1 = 3 nm without APS and 6 nm with APS (a reactively generated copolymer) Okamoto and Inoue, 1993... 

Next, we examine the possibilities of determining the dielectric constant of nanometer films by using the pure ellipsometric method or the combination of ellipsometric and reflectivity measurements. In the case of ellipsometry a convenient quantity is ratio SV Sh (or vice versa). On condition that JA and are measured at the same angle of incidence from Eqs. (1) and (2) we obtain... 

Next, in the case of transparent substrate the pure ellipsometric method is not applicable for the determination of e on the basis of approximate Eqs. (6) and (7) whereas the relation is independent of. If ellipsometric parameter 5A is... 

Many ingenious methods have been introduced to study protein adsorption. If the kinetics of the adsorption process are important, the ellipsometric method introduced by Rothen (3) is probably the best. In this method protein adsorption can be studied ijn situ from a solution. The method has been used to study the kinetics of both the adsorption of protein in single layers and in double layers that can occur in the immune-reaction. When protein such as bovine serum albumin (BSA) was adsorbed from a dilute solution onto a surface, after a delay of a few seconds, steady-state diffusion controlled the adsorption process and, consequently, the amount bound to the surface increased linearly with time. However, as the surface became covered, adsorption slowed down, because it was now limited by the number of available sites on the surface. The final layer of BSA was roughly 2 nanometer thick. 

The ellipsometric method has been developed by Yukioka and Inoue (1991, 1994). The principles of the technique and the model used for calculating the thickness of the interphase are schematically illustrated in Figs. 4.13 and 4.14, respectively. The retardation (A) and reflection ratio (tan(i/<)) can be determined from the ellipsometric readings. The adopted model assumes the existence of four layers air, thin polymer-1, interphase, and thick polymer-2 (see Fig. 4.14). In the interphase the refractive index is assumed to be an average n = iti+ ni)H. Thus, one can compute the best value of the interfacial thickness, do, to fit the observed values of A and tan( ). The following relations were derived for the computation of d ... 

The ellipsometric method was used to study adsorbed DNA for the first time by Humphreys and Parsons [222], Since that time the sensitivity of this method has appreciably increased [223], The measurement of x-ray reflection enabled studies of the structure of very thin layers (down to several A) and the morphology of the interface [224]. 

A refractive index n = 0.4469 and an absorption index k=1.5934 have been obtained for a nearly stoichiometric LaSe single crystal with X = 632.8 nm at room temperature, using an ellipsometric method, Zhuze et al. [20]. The dispersion curves of n and k for an LaSe single crystal are shown in Fig. 21, derived from polarometric measurements by Zhuze [24]. 

With regards to stratified systems, it is noticeable that the layer thickness can, in principle, be determined by using the ellipsometric method. However, this does not hold for ultrathin films (monolayers and multilayers) because the infiuence of anisotropy, molecular density, and thickness cannot be discriminated in this case [68]. 

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