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# IEEE Transactions on Dielectrics and Electrical Insulation

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Displaying Results 1 - 19 of 19
• ### Pyroelectric activity of ferroelectric PT/PVDF-TRFE

Publication Year: 2000, Page(s):517 - 522
Cited by:  Papers (32)
| | PDF (596 KB)

This paper studies the pyroelectric coefficient of 0-3 composites consisting of 27%vol lead titanate (PT) powder embedded in a vinylidene fluoride-trifluoroethylene copolymer (PVDF-TRFE) matrix. The constituent phases of the composites have been polarized in four possible ways: only the copolymer polarized; only the ceramic polarized; the copolymer and ceramic phases polarized in the same directio... View full abstract»

• ### Space charge behavior in low-density polyethylene

Publication Year: 2000, Page(s):503 - 508
Cited by:  Papers (53)
| | PDF (356 KB)

The space charge distribution in low-density polyethylene (LDPE) was measured with the pulsed electroacoustic (PEA) method. We used three types of LDPE: LDPE-L and LDPE-H were prepared by the high pressure process, and m-LDPE was polymerized with a metallocene catalyst. Space charge in LDPE strongly depended upon the electrode material. Semiconductive electrodes enhanced carrier injection into LDP... View full abstract»

• ### The method of matching resonance frequencies in coupled transmitter PVDF/TRFE diaphragms

Publication Year: 2000, Page(s):498 - 502
Cited by:  Papers (4)  |  Patents (4)
| | PDF (376 KB)

The influence of thermal aging on the resonance frequency and electric impedance of polyvinylidenefluoride (PVDF) type polymer films was studied with the aim to apply thermal treatment to modify and tune the parameters of polymer electromechanical transducers. Results of our study show that thermal treatment of PVDF/TRFE 75/25 copolymer in the temperature range 50 to 125°C (10 min) can be appl... View full abstract»

• ### Spontaneous polarization and orientational dynamics of polar rod-like molecules in host/guest materials

Publication Year: 2000, Page(s):523 - 530
Cited by:  Papers (2)
| | PDF (856 KB)

The polar domain structure and dynamics of host/guest materials which include polar rodlike molecules were investigated by pyroelectric and dielectric techniques. Using scanning pyroelectric microscopy (SPEM), spatially resolved information on a μm scale was obtained of the 3-D domain structure of the polarization caused by an acentric host lattice and/or the polar arrangement of dipolar guest ... View full abstract»

• ### Dielectric and electrical properties of polycrystalline rocks at various hydration levels

Publication Year: 2000, Page(s):493 - 497
Cited by:  Papers (9)
| | PDF (456 KB)

The dielectric properties of low porosity natural polycrystalline rock material (marble) were investigated using broadband 10-2 to 106 Hz) dielectric relaxation spectroscopy at several hydration levels, from dry to fully hydrated samples, with the water content varying from 0 to 0.08% g water/g dry material. The measured dielectric response is characterized by large low frequ... View full abstract»

• ### A finite element method for the determination of space charge distributions in complex geometry

Publication Year: 2000, Page(s):556 - 560
Cited by:  Papers (12)
| | PDF (388 KB)

Electrical breakdown in insulators very often initiate near high field regions of the structure, as found near small-radius impurities or at electrode defects. This is attributed to the development of localized space charges. For this reason many efforts have been made to determine such charge. Various techniques are now available, but they are not directly applicable to complex geometries where i... View full abstract»

• ### Corona poling and electroactivity in a side-chain methacrylate copolymer

Publication Year: 2000, Page(s):572 - 577
Cited by:  Papers (5)
| | PDF (488 KB)

The corona poling process and the decay in electro-optic activity were investigated for side-chain methacrylate (MA) copolymers functionalized with different weight percentages of chromophore disperse red-13. In order to obtain the maximum electro-optic activity, the efficiency of the corona poling process was investigated. The poling time, temperature and grid voltage of the corona triode were va... View full abstract»

• ### Polarization fatigue in ferroelectric polymers

Publication Year: 2000, Page(s):489 - 492
Cited by:  Papers (14)
| | PDF (328 KB)

Ferroelectric materials are characterized by a spontaneous polarization which can be switched by an applied electric field. In many ferroelectrics the magnitude of the reversed polarization is observed to decrease when the polarization is switched many times. In ferroelectric polymers a significant decrease in reversed polarization may be observed after ~3000 cycles, and the reduction can be ~50% ... View full abstract»

• ### TSDC in epoxy networks of well-controlled architecture: Experimental evidence for local and non-local relaxation process

Publication Year: 2000, Page(s):551 - 555
Cited by:  Papers (3)
| | PDF (448 KB)

Local and non-local relaxation processes were distinguished by investigating the heating rate dependence of the thermally stimulated discharge current (TSDC) line-shape in the case of three epoxy networks of well-controlled architecture. These networks were chosen because their chain dynamics differ by the relative extent of their local and short-scale cooperative molecular motions, as a consequen... View full abstract»

• ### Polarization and space charge behavior of unaged and electrically aged crosslinked polyethylene

Publication Year: 2000, Page(s):474 - 479
Cited by:  Papers (22)
| | PDF (504 KB)

The behavior of crosslinked polyethylene (XLPE) for HV cable insulation under electrical stress is discussed in the paper, referring to specimens unaged and electrically aged. Polarization and space charge features are considered. The behavior of the examined insulation is evaluated through the universal' model for polarization and space-charge associated quantities, such as the dc threshold for ... View full abstract»

• ### Molecular dynamics in homo, diblock and triblock polymers studied by dielectric relaxation spectroscopy

Publication Year: 2000, Page(s):509 - 516
Cited by:  Papers (2)
| | PDF (796 KB)

The dynamics of poly(oxybutylene) chains was investigated in comparison to that of poly(oxybutylene) blocks in solid semicrystalline poly(oxyethylene)-poly(oxybutylene) (EB) diblock copolymers and poly(oxyethylene)-poly(oxybutylene)-poly(oxyethylene) (EBE) triblock copolymers, using broadband dielectric relaxation spectroscopy (10-2 to 109 Hz). The B homopolymers and the B bl... View full abstract»

• ### Effect of dipolar arrays on the localization of charge carriers in molecular materials

Publication Year: 2000, Page(s):531 - 536
Cited by:  Papers (24)
| | PDF (508 KB)

The paper presents results of calculations of the depth and distribution of local states for charge carriers created by polar impurities in a model molecular material. Equations resulting from the electrostatic model due to Lyons have been employed in the calculations. The presence of polar species in a non-polar molecular material locally modifies the polarization energy, thus creating local stat... View full abstract»

• ### The influence of electrodes and conditioning on space charge accumulation in XLPE

Publication Year: 2000, Page(s):561 - 571
Cited by:  Papers (20)
| | PDF (796 KB)

The accumulation of space charge in planar crosslinked polyethylene (XLPE) samples under dc electric fields at room temperature was investigated using the pulsed electroacoustic (PEA) method. Three different organic semiconductor (semicon) materials containing carbon black at concentrations ~30 %wt, and vacuum-evaporated gold, were used as electrodes. Three different conditioning procedures were i... View full abstract»

• ### Preparation and characterization of novel piezoelectric and pyroelectric polymer electrets

Publication Year: 2000, Page(s):578 - 586
Cited by:  Papers (33)
| | PDF (800 KB)

The preparation and characterization of novel piezoelectric and pyroelectric electrets is discussed with respect to their electret properties. Charged heterogeneous electrets, like closed-cell microporous polypropylene (pp) foams and soft-hard' fluoropolymer hybrids are shown to yield large quasi-static and dynamic piezoelectric responses, indistinguishable from true piezoelectricity. Piezoelectr... View full abstract»

• ### Porous PTFE space-charge electrets for piezoelectric applications

Publication Year: 2000, Page(s):480 - 488
Cited by:  Papers (61)  |  Patents (2)
| | PDF (772 KB)

Porous polytetrafluoroethylene (PTFE) films were positively or negatively corona charged at room or elevated temperatures. Their charge storage behavior was investigated by means of isothermal surface potential measurements in direct comparison to nominally nonporous samples of the same polymer. It was found that porosity may lead to significantly enhanced surface-charge stability for both polarit... View full abstract»

• ### Piezoelectricity in cellular electret films

Publication Year: 2000, Page(s):537 - 542
Cited by:  Papers (133)  |  Patents (1)
| | PDF (592 KB)

Permanently charged films with a cellular or porous structure represent a new family of polymer electrets. These materials show piezoelectric properties with high piezoelectric constants. The electromechanical response equations of such films are derived for their operation as sensors and as actuators. Experimental results are also presented for cellular polypropylene (pp). In particular, measurem... View full abstract»

• ### A novel displacement component in PVDF and its role in ferroelectric switching

Publication Year: 2000, Page(s):543 - 550
Cited by:  Papers (18)
| | PDF (788 KB)

In this paper we describe the detection of a novel frequency dependent displacement current in polyvinylidenefluoride (PVDF). This component was derived from electrical switching experiments performed by the application of voltage pulses of different duration, followed by defined short circuit times. By means of the results so obtained, a complete account of all relevant displacement contributions... View full abstract»

• ### Electrets: materials, properties, applications

Publication Year: 2000, Page(s): 465
| | PDF (92 KB)

First Page of the Article
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• ### Piezoelectricity, pyroelectricity and ferroelectricity in biomaterials: Speculation on their biological significance

Publication Year: 2000, Page(s):466 - 473
Cited by:  Papers (20)
| | PDF (696 KB)

Many thousands of papers have been published on the piezoelectric, pyroelectric and ferroelectric properties of single crystals, ceramics, polymers and liquid crystals. Yet fewer than 100 papers have appeared on these properties in biological materials. Piezoelectric and pyroelectric effects have been measured on a number of plant and animal tissues and the possible existence of ferroelectricity h... View full abstract»

## Aims & Scope

IEEE Transactions on Dielectrics and Electrical Insulation contains topics that are concerned with dielectric phenomena and measurements, with development and characterization of gaseous, vacuum, liquid and solid electrical insulating materials and systems; and with utilization of these materials in circuits and systems under condition of use.

Full Aims & Scope

Editor-in-Chief
Reuben Hackam