Antioxidants, neutral phthalocyanine and titanium dioxide were added to "pure" linear low density polyethylene resin, and films were extruded. Charge storage, and conduction properties, were measured using TSCD and open and short circuit TSC; and TSPC, respectively. Antioxidants increased negative and positive storage level and reduced conduction activation energies, but had little effect on lifetime. 0.01 wt. % of phthalocyanine increased lifetime in the dark (x 5) and conduction activation energy. Trapping may take place by the cage-like amine structure. 5 wt. % of titanium dioxide increased charge lifetime by a factor of roughly 7. Defect traps were annealed out at low concentrations, and new deep traps introduced by the titanium dioxide itself at all concentrations. Additive-matrix boundary trapping is another possibility for the latter two additives.
{"title":"Bulk modification of charge trapping and conductivity in linear low density polyethylene","authors":"M. Perlman, S. Haridoss","doi":"10.1109/TEI.1987.298956","DOIUrl":"https://doi.org/10.1109/TEI.1987.298956","url":null,"abstract":"Antioxidants, neutral phthalocyanine and titanium dioxide were added to \"pure\" linear low density polyethylene resin, and films were extruded. Charge storage, and conduction properties, were measured using TSCD and open and short circuit TSC; and TSPC, respectively. Antioxidants increased negative and positive storage level and reduced conduction activation energies, but had little effect on lifetime. 0.01 wt. % of phthalocyanine increased lifetime in the dark (x 5) and conduction activation energy. Trapping may take place by the cage-like amine structure. 5 wt. % of titanium dioxide increased charge lifetime by a factor of roughly 7. Defect traps were annealed out at low concentrations, and new deep traps introduced by the titanium dioxide itself at all concentrations. Additive-matrix boundary trapping is another possibility for the latter two additives.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"3 1","pages":"88-93"},"PeriodicalIF":0.0,"publicationDate":"1987-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87138646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Propagating arc discharges are the result of electrical breakdown in electron-beam-charged dielectrics. For incident electron accelerating voltages in the range of kilovolts to tens of kilovolts, the charge accumulation is primarily within a few micrometers of the exposed surface, so that the propagating subsurface arc frequently bursts through the surface, ejecting ionized debris and an appreciable fraction of the accumulated electrons. This blowoff current can reach a peak value of hundreds or even thousands of amperes and thus, when it occurs on spacecraft materials, severe interference to control systems can be the result. The present state of understanding of this phenomenon will be reviewed.
{"title":"Surface arc discharges on spacecraft dielectrics","authors":"K. Balmain","doi":"10.1109/TEI.1986.349087","DOIUrl":"https://doi.org/10.1109/TEI.1986.349087","url":null,"abstract":"Propagating arc discharges are the result of electrical breakdown in electron-beam-charged dielectrics. For incident electron accelerating voltages in the range of kilovolts to tens of kilovolts, the charge accumulation is primarily within a few micrometers of the exposed surface, so that the propagating subsurface arc frequently bursts through the surface, ejecting ionized debris and an appreciable fraction of the accumulated electrons. This blowoff current can reach a peak value of hundreds or even thousands of amperes and thus, when it occurs on spacecraft materials, severe interference to control systems can be the result. The present state of understanding of this phenomenon will be reviewed.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"28 1","pages":"597-601"},"PeriodicalIF":0.0,"publicationDate":"1986-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82291607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interfaces and surfaces are always involved with electrets and frequently, if not invariably, exert a controlling influence on their properties. Although classical featureless models have often been used to describe the behaviour, especially where contact to metal electrodes is involved, the situation is much more complex. The nature of interfaces and contacts and of charge transfer across them is reviewed using the concepts of modern molecular electronics and electrochemistry. The effect of blocking and non-blocking conditions and the special behaviour at free surfaces is considered. The roles of structure and local order especially for polymeric electrets and the influence of ionic and polar impurities in determining the magnitude, life-time and transport of charges in electret materials will be outlined.
{"title":"Electrical effects at interfaces and surfaces","authors":"T. Lewis","doi":"10.1109/TEI.1986.349063","DOIUrl":"https://doi.org/10.1109/TEI.1986.349063","url":null,"abstract":"Interfaces and surfaces are always involved with electrets and frequently, if not invariably, exert a controlling influence on their properties. Although classical featureless models have often been used to describe the behaviour, especially where contact to metal electrodes is involved, the situation is much more complex. The nature of interfaces and contacts and of charge transfer across them is reviewed using the concepts of modern molecular electronics and electrochemistry. The effect of blocking and non-blocking conditions and the special behaviour at free surfaces is considered. The roles of structure and local order especially for polymeric electrets and the influence of ionic and polar impurities in determining the magnitude, life-time and transport of charges in electret materials will be outlined.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"51 1","pages":"75-87"},"PeriodicalIF":0.0,"publicationDate":"1986-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75617188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The polarization reversal and the ferroelectric hysteresis loop have been studied for copolymers of vinylidene fluoride VDF and trifluoroethylene TrFE with 47.2, 63.0, 70.7, and 86.8 mol-% TrFE in the high voltage field up to 100 MVm−1 at 5 to 100 mHz over a wide range of temperature. The copolymers exhibited two current peaks associated with the polarization process at different field intensities : one at a higher field Eh was due to the polarization reversal; the other at a lower field E1 occurred in the opposite polarity, indicating the depolarization process at high temperature. These two current peaks were related with the double hysteresis loop in the copolymers. As temperature was decreased, E1 lowered crossing zero and changed in the polarization field. The temperature at which E reduced to zero was 321, 277, 253, and 239 K for 47.2, 63.0, 70.7, and 86.8 mol-% TrFE content, respectively.
{"title":"Polarization reversal and double hysteresis loop in copolymers of vinylidene fluoride and trifluoroethylene","authors":"N. Koizumi, Y. Murata, H. Tsunashima","doi":"10.1109/TEI.1986.348913","DOIUrl":"https://doi.org/10.1109/TEI.1986.348913","url":null,"abstract":"The polarization reversal and the ferroelectric hysteresis loop have been studied for copolymers of vinylidene fluoride VDF and trifluoroethylene TrFE with 47.2, 63.0, 70.7, and 86.8 mol-% TrFE in the high voltage field up to 100 MVm−1 at 5 to 100 mHz over a wide range of temperature. The copolymers exhibited two current peaks associated with the polarization process at different field intensities : one at a higher field Eh was due to the polarization reversal; the other at a lower field E1 occurred in the opposite polarity, indicating the depolarization process at high temperature. These two current peaks were related with the double hysteresis loop in the copolymers. As temperature was decreased, E1 lowered crossing zero and changed in the polarization field. The temperature at which E reduced to zero was 321, 277, 253, and 239 K for 47.2, 63.0, 70.7, and 86.8 mol-% TrFE content, respectively.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"12 1","pages":"936-941"},"PeriodicalIF":0.0,"publicationDate":"1986-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74501496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1985-12-01DOI: 10.1109/ISE.1985.7341495
T. Oda, T. Utsumi, T. Kumano, M. Itami
Photo-Stimulated Detrapping Currents (PSDCs) of FEP-teflon electrets charged by corona at 150°C were observed to understand the charge storage mechanism. Monochromatic light of a deuterium lamp (4–6.5 eV) or a mercury lamp (4.9 eV) was irradiated to the sample electrets at a room temperature. A threshold energy of light to generate PSDCs was found to be 4.9 eV. The experimental results indicate that there exists only single trapping level (4.9 eV) to be activated by a deuterium lamp. However, at a higher temperature, the another photo-sensitive detrapping current was also observed by the irradiation of the same light.
{"title":"Observation of photo-stimulated detrapping currents of FEP teflon electrets","authors":"T. Oda, T. Utsumi, T. Kumano, M. Itami","doi":"10.1109/ISE.1985.7341495","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341495","url":null,"abstract":"Photo-Stimulated Detrapping Currents (PSDCs) of FEP-teflon electrets charged by corona at 150°C were observed to understand the charge storage mechanism. Monochromatic light of a deuterium lamp (4–6.5 eV) or a mercury lamp (4.9 eV) was irradiated to the sample electrets at a room temperature. A threshold energy of light to generate PSDCs was found to be 4.9 eV. The experimental results indicate that there exists only single trapping level (4.9 eV) to be activated by a deuterium lamp. However, at a higher temperature, the another photo-sensitive detrapping current was also observed by the irradiation of the same light.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"7 1","pages":"288-293"},"PeriodicalIF":0.0,"publicationDate":"1985-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80065830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1985-09-01DOI: 10.1109/ISE.1985.7341472
R. Capelletti, A. Gainotti, M. Suszyńska
The features of C-peak appearing in the ITC spectra (300–370 K) of alkali halides doped with divalent cations are unusual. Its position and amplitude Hc are functions of thermal treatment, plastic deformation, impurity concentration, sample thickness and nature of contacts. Hc is strongly reduced by plastic deformation, according to the square root of the screw dislocation density; it is partially recovered by sample annealing in the 290–350 K range. Most of the results, obtained in a wide class of systems (such as LiF:Be, KC1 and NaCl:Eu, Pb, Ni), can be explained in terms of interfacial polarization induced by Cottrell atmosphere surrounding dislocations. The role of air gaps between sample and electrodes is also considered.
{"title":"ITC technique to monitor interactions between dislocations and aliovalent cations in alkali halides","authors":"R. Capelletti, A. Gainotti, M. Suszyńska","doi":"10.1109/ISE.1985.7341472","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341472","url":null,"abstract":"The features of C-peak appearing in the ITC spectra (300–370 K) of alkali halides doped with divalent cations are unusual. Its position and amplitude Hc are functions of thermal treatment, plastic deformation, impurity concentration, sample thickness and nature of contacts. Hc is strongly reduced by plastic deformation, according to the square root of the screw dislocation density; it is partially recovered by sample annealing in the 290–350 K range. Most of the results, obtained in a wide class of systems (such as LiF:Be, KC1 and NaCl:Eu, Pb, Ni), can be explained in terms of interfacial polarization induced by Cottrell atmosphere surrounding dislocations. The role of air gaps between sample and electrodes is also considered.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"104 5 1","pages":"151-156"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75613151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1985-09-01DOI: 10.1109/ISE.1985.7341528
O. N. Oliveira, G. Ferreira
Measurements of the grid to plate current-voltage characteristics of the corona triode are reported. A space charge limited current (SCLC) characteristic is observed to hold for low values of the plate current Ip, provided that the grid voltage Vg is corrected by a counter potential Vr. The analysis of experimental results indicates that Vr is due both to penetration of field lines through the grid and to the corona wind. However, departure from SCLC regime is observed at higher plate currents. In the calculation, a layer of recombination centers is substituted for the grid. The model fits the whole characteristics and leads to reasonable values of the parameters defined by the model.
{"title":"Grid to plate current-voltage characteristics of a corona triode","authors":"O. N. Oliveira, G. Ferreira","doi":"10.1109/ISE.1985.7341528","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341528","url":null,"abstract":"Measurements of the grid to plate current-voltage characteristics of the corona triode are reported. A space charge limited current (SCLC) characteristic is observed to hold for low values of the plate current Ip, provided that the grid voltage Vg is corrected by a counter potential Vr. The analysis of experimental results indicates that Vr is due both to penetration of field lines through the grid and to the corona wind. However, departure from SCLC regime is observed at higher plate currents. In the calculation, a layer of recombination centers is substituted for the grid. The model fits the whole characteristics and leads to reasonable values of the parameters defined by the model.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"61 1","pages":"500-505"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72965643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently nondestructive methods have been developed which make it possible to investigate layered charge and dipolar distributions in dielectric materials within an order of 1 μm resolution. These direct methods which do not use mathematical deconvolution techniques are the LIPP-[1] and the PPS-method [2]. The PPS-method operating with an almost ideal acoustic step excitation results in getting an 1:1-image of the longitudinal piezoelectric distribution within a thin film as demonstrated for PVDF by Haardt [3J. The results are consistent with charge compensated polarization layers within incompletely poled films. In order to obtain more informations on the possible reasons for these distributions we investigated the time dependence of the step response signal during poling. The nature of the compensation charges appears to be ionic as consistent with the pressure dependence of conductance.
{"title":"Charge and polarization dynamics in polymer films","authors":"K. Holdik, W. Eisenmenger","doi":"10.18419/OPUS-4940","DOIUrl":"https://doi.org/10.18419/OPUS-4940","url":null,"abstract":"Recently nondestructive methods have been developed which make it possible to investigate layered charge and dipolar distributions in dielectric materials within an order of 1 μm resolution. These direct methods which do not use mathematical deconvolution techniques are the LIPP-[1] and the PPS-method [2]. The PPS-method operating with an almost ideal acoustic step excitation results in getting an 1:1-image of the longitudinal piezoelectric distribution within a thin film as demonstrated for PVDF by Haardt [3J. The results are consistent with charge compensated polarization layers within incompletely poled films. In order to obtain more informations on the possible reasons for these distributions we investigated the time dependence of the step response signal during poling. The nature of the compensation charges appears to be ionic as consistent with the pressure dependence of conductance.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"31 1","pages":"553-558"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75579693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1985-09-01DOI: 10.1109/ISE.1985.7341491
K. Ngai, A. Rajagopal, R. Rendell, S. Teitler
The contributions of R. and F. Kohlrausch to the description of mechanical and dielectric relaxation in complex systems are briefly cited as background for a discussion of a theory of relaxation that derives both the Kohlrausch time-dependent relaxation rate that can be expressed in the form W0(ωct)−n, 0p)1−n] relaxation function. Here W0 is the fundamental relaxation rate of some well-defined primitive relaxation species. Two coupled predictions are obtained. They have been experimentally verified and have led to many successful applications to conductivity and polarization phenomena relevant to electrets, as well as viscoelasticity, rheology, etc.
{"title":"Mechanisms for Kohlrausch relaxations in charging and polarization phenomena","authors":"K. Ngai, A. Rajagopal, R. Rendell, S. Teitler","doi":"10.1109/ISE.1985.7341491","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341491","url":null,"abstract":"The contributions of R. and F. Kohlrausch to the description of mechanical and dielectric relaxation in complex systems are briefly cited as background for a discussion of a theory of relaxation that derives both the Kohlrausch time-dependent relaxation rate that can be expressed in the form W<inf>0</inf>(ω<inf>c</inf>t)<sup>−n</sup>, 0<n<l, and the Kohlrausch fractional exponential exp[−(t/τ<inf>p</inf>)<sup>1−n</sup>] relaxation function. Here W<inf>0</inf> is the fundamental relaxation rate of some well-defined primitive relaxation species. Two coupled predictions are obtained. They have been experimentally verified and have led to many successful applications to conductivity and polarization phenomena relevant to electrets, as well as viscoelasticity, rheology, etc.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"78 1","pages":"265-270"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74203111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1985-09-01DOI: 10.1109/ISE.1985.7341594
C. F. Groner, M. Hirsh
This paper compares various techniques for poling PVF2 Him for piezoelectric and pyroelectric applications. Criteria for the choice of a technique include high piezo and pyro activities of the resulting film, low failure rate due to electrical breakdown during poling, and long-term stability of activities. The techniques discussed include field poling at room and elevated temperatures, and corona discharge under various conditions. The effects of various film pretreatments and film electrode configurations on the poling process will also be presented.
{"title":"Comparison of poling techniques for inducing piezoelectric behavior in PVF2","authors":"C. F. Groner, M. Hirsh","doi":"10.1109/ISE.1985.7341594","DOIUrl":"https://doi.org/10.1109/ISE.1985.7341594","url":null,"abstract":"This paper compares various techniques for poling PVF2 Him for piezoelectric and pyroelectric applications. Criteria for the choice of a technique include high piezo and pyro activities of the resulting film, low failure rate due to electrical breakdown during poling, and long-term stability of activities. The techniques discussed include field poling at room and elevated temperatures, and corona discharge under various conditions. The effects of various film pretreatments and film electrode configurations on the poling process will also be presented.","PeriodicalId":6451,"journal":{"name":"1985 5th International Symposium on Electrets (ISE 5)","volume":"5 1","pages":"912-917"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80376921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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