Metal-polymer film materials dielectric properties

An example of this approach is represented by the growth of 3-D coordination polymers with SCO properties via stepwise adsorption reactions for multilayer films based entirely on intra- and interlayer coordination bonds Fe(pyrazine) [Pt(CN) ] [218, 219], Indeed, after functionalization of the surface with the appropriate anchoring layer the coordination polymer is built in a stepwise fashion, alternating the metal ion (Fe "), the platinum salt ([Pt(CN) ] ), and pyrazine. The polymer shows many interesting properties, with the SCO transition accompanied by a variation in the dielectric constant of the material accompanied by a room temperature hysteresis of the dielectric constants. This dielectric hysteretic property may be useful in building molecular memory devices that can store information by high- and low-capacitance states. What must be remarked here is that these appealing properties cannot be exploited in bulk materials, but only in thin films. 

For the calculations of the optical properties of polymer films with embedded nanoparticles, two routes can be selected. In the exact route, the extinction cross sections Cact(v) of single particles are calculated. The calculated extinction spectra for single particles—or, better, a summation of various excitation spectra for a particle assembly—can be compared with the experimental spectra of the embedded nanoparticles. In the statistic route, an effective dielectric function e(v) is calculated from the dielectric function of the metal e(T) and of the polymer material po(v) by using a mixing formula, the so-called effective medium theory. The optical extinction spectra calculated from the effective dielectric functions by using the Fresnel formulas can be compared with the experimental spectra. 

High performance polymer films and coating materials are increasing being required by the electronics industry for use as interlayer dielectrics and as passivation layers. Aromatic polyimides are general the polymers of choice for these applications because of their unique combination of chemical, physical, and mechanical properties (i). Another class of polymers which have been investigated for these applications are the po arylene ether)s that can be prepared by the nucleophilic displacement of activated aromatic dihalides alkali metal bisphenoxides. Heterocycles such as benzoxazoles (2), imidazoles (5), phenylquinoxalines (.4), and 1,2,4-triazoles (5) have been incorporated within poly(arylene ethers) utilizing this thetic procedure. 

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