P1F-4 Revisiting LGT Dielectric Constants and Temperature Coefficients Up to 120°C

2007 ◽  
Author(s):  
P. M. Davulis ◽  
B. T. Sturtevant ◽  
S. L. Duy ◽  
M. Pereira da Cunha
Keyword(s):  
Dielectric Constants ◽  
Temperature Coefficients

PRELIMINARY OBSERVATIONS OF THE DIELECTRIC CONSTANTS OF VAPORS ADSORBED ON ACTIVATED SILICA

1947 ◽  
Vol 25b (6) ◽  
pp. 566-574 ◽  
Author(s):  
R. McIntosh ◽  
L. McLeod ◽  
H. S. Johnson ◽  
N. Hollies
Keyword(s):  
Dielectric Constant ◽  
Ethylene Oxide ◽  
Silica Gel ◽  
Dielectric Constants ◽  
Ethyl Chloride ◽  
Bulk Liquid ◽  
Temperature Coefficients ◽  
Capacity Change

A measure of the dielectric constants of several substances adsorbed on silica gel has been obtained by measuring the change in the capacity of an electrical condenser when measured amounts of the substances were adsorbed on silica gel situated between the plates of the condenser. The substances examined were ethyl chloride, n-butane, and ethylene oxide. The plot of capacity change vs. amount adsorbed was found, in all cases, to consist of two or more quite distinct sections, each approximating to linearity. The temperature coefficients of dielectric constant were evaluated. The dielectric constant calculated for adsorbed n-butane was close to that calculated for the bulk liquid, whereas the value calculated for adsorbed ethyl chloride was significantly lower than the value calculated for the liquid.

scholarly journals On the direct determination of the electrostatic moments of molecules

1929 ◽  
Vol 124 (795) ◽  
pp. 689-698 ◽  
Keyword(s):  
Dielectric Constant ◽  
Direct Determination ◽  
Negative Temperature ◽  
Dielectric Constants ◽  
Temperature Coefficients ◽  
Different Temperatures

According to Faraday's ideas, the specific inductive capacity of a substance is due to the polarisation of the molecules as wholes. This is the basis of the old Clausius-Mosotti theory of dielectrics, on which it is shown first that the polarisation P is proportional to the polarising field, i. e. , P = k E, k being the dielectric constant, and second that δ being the density of the dielectric, k - 2/ k + 2 ·1/δ = constant. Now it is known that some substances have large negative temperature coefficients for their dielectric constants which cannot thus be accounted for. To provide for this Debye proposed the theory that the molecules were permanently polarised and that they were systematically orientated in the field. This leads to the equation k - 2/ k + 2 = a T -1 + b T -2 , to represent the change of specific inductive capacity with temperature. This theory has been developed by Gans and others, and a number of measurements have been made by Smyth and others, who have found the molecular moments of many substances by measuring the dielectric constants at different temperatures.

High dielectric constant and small temperature coefficient bismuth-based dielectric compositions

1990 ◽  
Vol 5 (8) ◽  
pp. 1752-1762 ◽  
Author(s):  
H. C. Ling ◽  
M. F. Yan ◽  
W. W. Rhodes
Keyword(s):  
Temperature Coefficient ◽  
Room Temperature ◽  
Dissipation Factor ◽  
Dielectric Constants ◽  
Compositional Variation ◽  
Multilayer Ceramic Capacitors ◽  
Temperature Coefficients ◽  
Compositional Changes ◽  
High Dielectric ◽  
High Silver

We have studied the crystal structure and the dielectric properties of a scries of Bi-based ceramic compositions as a function of compositional variation and sintering temperature. These dielectrics have dielectric constants hetween 70 and 165 and their temperature coefficients are within ±500 × 10−6/°C. The precise temperature coefficient can be controlled via compositional changes such that dielectrics with temperature coefficients within ±50 × 10−6/°C are easily obtainable. The room temperature dissipation factor is smaller than 0.001 or equivalently, the Q value is greater than 1000. The electrical resistivity is greater than 1014 ohm-cm. Furthermore, these dielectrics are sinterable below 960 °C, rendering it possible to use silver or high silver metallization as the internal electrode in making the multilayer ceramic capacitors.

Microstructure and Temperature Stability of Ca Substituted Forsterite Ceramics

2011 ◽  
Vol 117-119 ◽  
pp. 606-609
Author(s):  
Kai Xin Song ◽  
Peng Zheng ◽  
Xiao Ping Hu ◽  
Jiang Xiang Deng ◽  
Jun Wu ◽  
...  
Keyword(s):  
Solid State ◽  
Resonant Frequency ◽  
Crystalline Phase ◽  
Temperature Stability ◽  
Dielectric Constants ◽  
Strongly Correlated ◽  
Quality Factors ◽  
Temperature Coefficients ◽  
Solid State Route ◽  
Conventional Solid State Route

In this paper, the dependance of microstructures on temperature stability of the (Mg1-xCax)2SiO4 (0≤x≤0.5) ceramics prepared by the conventional solid-state route were investigated. The XRD and SEM testing results showed the (Mg1-xCax)2SiO4 ceramics were mainly composed of both forsterite (Mg2SiO4) phase and Monticouite (MgCaSiO4) phase. Significantly, with increasing x, the ceramic temperature coefficients of resonant frequency (τf) were strongly correlated to the ceramic crystalline phase compositions and could be adjusted to near zero value through changing the contents of both phases. And its dielectric constants (er) were kept in the range of 6.8 to 8.7, and the quality factors (Q×f value) in the range of 18, 080 GHz to 55, 840 GHz at 15GHz.

Dielectric Properties of Bismuth Layer-Structured Oxide Thin Films with Preferential Crystal Orientation at High-Temperature

2011 ◽  
Vol 485 ◽  
pp. 191-194
Author(s):  
Yuki Mizutani ◽  
Junichi Kimura ◽  
Itaru Takuwa ◽  
Tomoaki Yamada ◽  
Hiroshi Funakubo ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Chemical Solution Deposition ◽  
Crystal Orientation ◽  
Atmospheric Temperature ◽  
Dielectric Constants ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Temperature Coefficients ◽  
Preferential Crystal Orientation

Thin films of MBi4Ti4O15 (M = Ca and Sr) with preferential crystal orientation were fabricated using underneath perovskite layers on various substrates. One-axis BLSD films on (100)LaNiO3/(111)Pt/Ti/(100)Si and epitaxial BLSD films on (100)SrRuO3//(100)SrTiO3 were fabricated by chemical solution deposition (CSD). Dielectric constants of the CaBi4Ti4O15 and SrBi4Ti4O15 films on (100)LaNiO3/(111)Pt/Ti/(100)Si were approximately 250, while those on (100)SrRuO3//(100)SrTiO3 were 220, respectively. The temperature coefficients of capacitance (TCCs) of these films were below 10% in atmospheric temperature range between R.T. and 300°C, which is significantly smaller than those of conventional (Ba,Sr)TiO3-based capacitors.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

The need of electron microscopy in the study of domains and domain walls in ferroelectrics

1994 ◽  
Vol 52 ◽  
pp. 550-551
Author(s):  
Wenwu Cao
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
High Mobility ◽  
Continuum Theory ◽  
Polarization Vector ◽  
Ferroelectric Materials ◽  
Dielectric Constants ◽  
Nonlocal Coupling ◽  
Cubic Symmetry ◽  
Gradient Energy

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,

Dielectric constants of biological objects

1963 ◽  
Vol 79 (4) ◽  
pp. 617-639 ◽  
Author(s):  
B.I. Sedunov ◽  
D.A. Frank-Kamenetskii
Keyword(s):  
Dielectric Constants ◽  
Biological Objects

Air Bridge Technology: A Comparison of Novel Interconnect Materials and Integration Schemes for Beyond 45 nm

2003 ◽  
Vol 766 ◽  
Author(s):  
Kenneth Foster ◽  
Joost Waeterloos ◽  
Don Frye ◽  
Steve Froelicher ◽  
Mike Mills
Keyword(s):  
Dielectric Constants ◽  
Advanced Technology ◽  
Effective Dielectric Constant ◽  
Device Performance ◽  
Interlayer Dielectric ◽  
Integration Schemes ◽  
Stepwise Reduction ◽  
Bridge Technology ◽  
Integrated Device ◽  
Compare And Contrast

AbstractThe electronics industry, in a continual drive for improved integrated device performance, is seeking increasingly lower dielectric constants (k) of the insulators that are used as interlayer dielectric (ILD) for advanced logic interconnects. As the industry continually seeks a stepwise reduction of the “effective” dielectric constant (keff), simple extendibility, leads to the consideration of the highest performance possible, namely air bridge technology. In this paper we will discuss requirements, integration schemes and properties for a novel class of materials that has been developed as part of an advanced technology probe into air bridge architecture. We will compare and contrast these potential technology offerings with other existing dense and porous ILD integration options, and show that the choice is neither trivial nor obvious.

Tuning the Electric Field Response of MOFs by Rotatable Dipolar Linkers

2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Structural Changes ◽  
Dielectric Behavior ◽  
Two Dimensions ◽  
Dielectric Constants ◽  
Electric Response ◽  
Dipole Strength ◽  
Metal Organic ◽  
Dynamics Simulations

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

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