Refractive of metals

In inorganic crystals atoms have higher and, as follows from Table 11.3 and the polarizabilities of clusters (Table 11.6), their refractions must be lower than in the molecular state. Because the Lorentz-Lorenz function approaches 1 when n oo, and metals have very high RIs (at X = 10 (.im, Cu has n = 29.7, Ag 9.9, Au 8.2, Hg 14.0, V 12.8, Nb 16.0, Cr 21.2, etc [147]), we assumed that R = V foi solid metals [148], These refractions of metals, Rm (Table 11.5, lower lines) in some cases are close to the additive values [13,14]. Rm cannot be applied directly to calculate molar refractions of crystalline inorganic compounds because of the differences in Nc, but can be used [149] to calculate refractions of metals for such Nc as they have in the structures of their compounds, using the formula... 

Batsanov SS (2003) On the covalent refractions of metals. Russ 1 Phys Chem 77 1374-1376 Noorizadeh S, Parhizgar M (2005) The atomic and group compressibility. 1 Mol Struct Theochem 725 23-26... 

Batsanov SS (1957) Atomic refractions of metals. Zhumal Neorganicheskoi Khimii 2 1221-1222 (in Russian)... 

Batsanov SS (1961) Covalent refractions of metals. J Struct Chem 2 337-342... 

Optical Properties. The index of refraction of a deposited material is sensitive to the film density. A lower index of refraction is found at less than bulk densities. The reflectance of a metallic surface is affected by the growth morphology of the film. 

Using the complex refractive index N = n + iK where i =- f—1 and Kis the absorption coefficient, the reflectivity R of metals and alloys is given by ... 

Bragg mirrors on periodic stacks of layers Periodic stacks of metal nanoparticles or dielectric layers with alternating high and low refractive index produce a desired reflectance of the mirror that depends on the thickness and the refractive index of the layers in the stack 16,17... 

One possibility to obtain a relatively small leakage into the substrate is to introduce a thin film of metal or absorbing layer such as a polymer or a dye with a complex dielectric function, or a thin layer of low refractive index material... 

This expression is independent of the film thickness. Thus, when one considers reflective monitoring of metal film etching, only at the interface between film and substrate will a change in reflectivity be observed due to the change in refractive index. Although this is extremely useful for end point detection one still must apply films of known thickness for cases in which etch rate information is desired. 

Krattiger B, Bruin GJM, Bruno AE. Hologram-based refractive-index detector for capillary electrophoresis—Separation of metal-ions. Analytical Chemistry 66, 1-8, 1994. 

Aqueous soap solutions can be obtained in three distinct forms, the sol form containing the ionic micelle, a clear gel, and a white opaque solid the curd. The sol and gel forms of various soaps have been examined by McBain and his co-workers and shown to differ only in elasticity and rigidity, whilst the electrical conductivity, refractive index, concentration of metallic ion and lowering of the vapour pressure are all identical, results to be anticipated on the fibrillar theory. The gel as we have seen is fibrillar in nature and the conversion of a gel into a curd is brought about by the removal of soap fi om solutions in the form of relatively coarse fibres, a process similar to crystallisation. The experiments of Laing and McBain... 

Khlebtsov NG, Trachuk LA, Mel nikov AG (2005) The effect of the size, shape, and structure of metal nanoparticles on the dependence of their optical properties on the refractive index of a disperse medium. Optics Spectrosc 98 77-83... 

The criterion propounded by Herzfeld in 1927 is instructive in understanding the metallic state. According to the Herzfeld criterion, a material is metallic when R/V I and insulating when R/V < 1. Here R is the molar refractivity of the atomic species in the gaseous state and V is the molar volume in the condensed state. This criterion explains the metallic character of the elements in nature (Edwards Sienko, 1983). Rao Ganguly (1986) have shown that the latent heat of vaporization provides a satisfactory criterion to delineate metallic elements from nonmetallic ones. 

Iron Oxide-Mica. Iron(III) oxide is suitable, like titanium dioxide, for coating of mica platelets. It combines a high refractive index (metallic luster) with good hiding power and weather resistance. 

IR spectra measurements as well as variation of the film thickness, shrinkage, and refractive index demonstrated substantial differences in the mechanisms of thermal decomposition of films prepared from the exclusively metal alkoxide precursor and from the metal alkoxides modified by 2-ethylhexanoic acid. These differences affect the evolution of film microstructure and thus determine the different dielectric properties of the obtained films. The dielectric permittivity of the films prepared from metal alkoxide solutions was relatively low (about 100) and showed weak dependence ofthe bias field. This fact may be explained by the early formation of metal-oxide network (mostly in the... 

---