Dielectric materials, defined

Chemical reagents are primarily concerned with dielectric liquids or solids. For metal oxides such as ferrites, however, magnetic losses occur in the microwave region. As for a dielectric material, a complex magnetic permeability is defined as given by Eq. (16) ... 

The scarcity of efficacious insulation candidates prompted the Semiconductor Industry Association to identify the criticality of low-k dielectric material development. Thus, in June 1995, Dow made a business commitment to invent a new material specifically tailored for the interconnect application. Specific performance targets were defined based on interactions with the industry, experience gained through Dow s earlier benzocyclobutene-based systems, finite element analysis of the anticipated interconnect structures, and principles of material sciences. 

Impedance spectroscopy is discussed in depth in the monograph edited by J.Ross Macdonald [17]. It has its origins in the classical work of K.S. Cole and R.H. Cole, published more than 60 years ago, concerned with methods of plotting the response of a dielectric material to applied voltages as a function of frequency. The method assists in identifying observed relaxation effects with processes at the atomic and microstructural levels. For a system having a single well-defined... 

The two key components in interconnect delays include the inherent resistance (R) of the metal lines and the capacitance (C) of the dielectric material in between the lines. The so-called RC delay is defined as the time required for the voltage at one end of a metal line to reach 63 % of its final value when a step input is presented at the other end of the line [18] ... 

No matter what the actual behaviour of the dielectric material is, there will always be some part of D(t) which follows the variation of E(t) precisely. The amount of this contribution to the total flux density is s Eit). Therefore it is possible and useful to introduce a susceptibility operator, which is defined by the equation... 

When a dielectric resonator is coupled with microwave circuits, the dielectric material responds to the frequency. The frequency selectivity of the microwave device depends on the loss quality of the materials. The selectivity Q ) of the dielectric materials is defined as the ratio of/ to A/, and the Q approximates the reciprocals of the loss factor (tan 5). The loss in DR (l/2 ) is the sum of the loss of dielectric materials (I/Qm). surface conduction HQ, and radiation loss (1/2,) ... 

The penetration depth Pa is defined as the distance from the surface of a lossy dielectric material at which the incident power drops to 37% (1/e). Skin depth is, in fact, equal to twice the penetration depth. 

If the gap between the plates is filled with a dielectric material, the capacitance increases by a constant factor characteristic of that material. The dielectric constant, e, is defined as ... 

We define the electret state of a dielectric material, in agreement with the definition of Refs. 9 and 10, as a metastable state characterized by a stored polarization. Its decay time must be assumed long with respect to the characteristic time of experiments performed on the material. 

In all real systems, some deviation from ideal behavior can he observed. If a potential is applied to a macroscopic system, the total current is the sum of a large number of microscopic current filaments, which originate and end at the electrodes. If the electrode surfaces are rough or one or more of the dielectric materials in the system are inhomogeneous, then all these microscopic current filaments would be different. In a response to a small-amplitude excitation signal, this would lead to frequency-dependent effects that can often be modeled with simple distributed circuit elements. One of these elements, which have found widespread use in the modeling of impedance spectra, is the so-called constant phase element (CPE). A CPE is defined as... 

Because dielectric material affects the force with which two oppositely charged plates attract each other, the dielectric constantmay also be defined as the relative effeet of the medium on this force of attraction, according to... 

The physics behind laser ablation is much more complicated than as explained above. Three characteristic timescales are involved to define the nature of laser interaction with a metallic material [1], They are the electron cooling time lattice heating time Tj, and laser pulse duration tl. For a nanosecond pulse laser, tL 3> Xi. the process is predominantly laser heating. For a picosecond pulse laser, x femtosecond pulse laser, the process is exclusively a laser ablation process. Laser ablation of semiconductor and dielectric materials involves different mechanisms [2]. 

Dimensionality According to the periodicity of dielectric materials along one or more axes, the dimension of photonic crystal is determined. This defines the working direction of photonic crystals to the incident light waves. Figure 1 shows examples of multidimensional photonic crystal structures whose refractive indices vary as a periodic function in the length scale. 

Dielectric dl-o- lek-trik [dia- -h electric] (1837) n. A material with electrical conductivity less than 10 S/cm (IpS/cm), thus so weakly conductive that different parts of a sheet can hold different electrical charges. In radio-frequency heating, the term dielectric is used for the material being heated. The term is also used for the non-conductive material separating the conductive elements of a capacitor. Polymeric materials are widely employed as dielectrics. The two most important properties of a dielectric are its dielectric constant and dielectric strength, defined below. Values for some polymeric and other dielectrics at 60 Hz and room temperature are listed here. 

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