237,217 research outputs found
Super Dielectric Materials
Evidence is provided that a class of materials with dielectric constants
greater than 100,000, herein called super dielectric materials (SDM), can be
generated readily from common, inexpensive materials.Comment: The first material ever with an intrinsic dielectric constant greater
than 100,000. Postulated to be a class of materials with super dielectric
propertie
Dependence of exciton transition energy of single-walled carbon nanotubes on surrounding dielectric materials
We theoretically investigate the dependence of exciton transition energies on
dielectric constant of surrounding materials. We make a simple model for the
relation between dielectric constant of environment and a static dielectric
constant describing the effects of electrons in core states, bonds and
surrounding materials. Although the model is very simple, calculated results
well reproduce experimental transition energy dependence on dielectric constant
of various surrounding materials.Comment: 5pages, 4 figure
Thermal conductivity and dielectric constant of silicate materials
Report on the thermal conductivity and dielectric constant of nonmetallic materials evaluates the mechanisms of heat transfer in evacuated silicate powders and establishes the complex dielectric constant of these materials. Experimental measurements and results are related to postulated lunar surface materials
Universal Electromagnetic Waves in Dielectric
The dielectric susceptibility of a wide class of dielectric materials
follows, over extended frequency ranges, a fractional power-law frequency
dependence that is called the "universal" response. The electromagnetic fields
in such dielectric media are described by fractional differential equations
with time derivatives of non-integer order. An exact solution of the fractional
equations for a magnetic field is derived. The electromagnetic fields in the
dielectric materials demonstrate fractional damping. The typical features of
"universal" electromagnetic waves in dielectric are common to a wide class of
materials, regardless of the type of physical structure, chemical composition,
or of the nature of the polarizing species, whether dipoles, electrons or ions.Comment: 19 pages, LaTe
Discharge characteristics of dielectric materials examined in mono-, dual-, and spectral energy electron charging environments
The effects of midenergy electrons on the charge and discharge characteristics of spacecraft dielectric materials and the data base from which basic discharge models can be formulated is expanded. Thin dielectric materials were exposed to low, mid combined low and mid, and spectral energy electron environments. Three important results are presented: (1) it determined electron environments that lead to dielectric discharges at potentials less negative than -5 kV; (2) two types of discharges were identified that dominate the kinds of discharges seen; and (3) it is shown that, for the thin dielectric materials tested, the worst-case discharges observed in the various environments are similar
Repulsive Casimir forces between solid materials with high refractive index intervening liquids
In order to explore repulsive Casimir/van der Waals forces between solid
materials with liquid as the intervening medium, we analyze dielectric data for
a wide range of materials as for example PTFE, polystyrene, silica and more
than twenty liquids. Although significant variation in the dielectric data from
different sources exist, we provide a scheme based on measured static
dielectric constants, refractive indices, and applying Kramers Kronig (KK)
consistency to dielectric data to create accurate dielectric functions at
imaginary frequencies. The latter is necessary for more accurate force
calculations via the Lifshitz theory allowing reliable predictions of repulsive
Casimir forces.Comment: 20 pages, 7 figures, 1 tabl
Complex permittivity measurements at Ka-Band using rectangular dielectric waveguide
The rectangular dielectric waveguide (RDWG) technique
has been developed for the determination of the dielectric
constant of materials from effective refractive index measurements in the Q andWbands. This paper describes the use of an optimization method in conjunction with the RDWG technique for the determination of both the dielectric constant and loss tangent of materials at Ka-Band. The effect of the uncertainty in the measured
sample thickness is presented
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