How the trapping of charges can explain the dielectric breakdown performance of alumina ceramics

Liebault, J.; Vallayer, J.; Gœuriot, D.; Tréheux, D.; Thévenot, F.

doi:10.1016/s0955-2219(00)00186-2

Cited by 113 publications

(63 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Unexplained until now, such experimental change of sign has been reported (see Figs. 3a and 7d in Liebault et al 2001), but more systematic investigations of this point are obviously needed.…”

Section: Experimental Supportmentioning

confidence: 99%

Charging in scanning electron microscopy “from inside and outside”

Cazaux¹

2004

Scanning

View full text Add to dashboard Cite

Summary: This paper is an attempt to analyse most of the complicated mechanisms involved in charging and discharging of insulators investigated by scanning electron microscopy (SEM). Fundamental concepts on the secondary electron emission (SEE) yield from insulators combined with electrostatics arguments permit to reconsider, first, the widespread opinion following which charging is minimised when the incident beam energy E 0 is chosen to be equal to the critical energy E°2 , where the nominal total yield δ°+η°= 1. For bare insulators submitted to a defocused irradiation, it is suggested here that the critical energy under permanent irradiation E C 2 corresponds to a range of primary electrons, R, and nearly equals the maximum escape depth of the secondary electrons, r. This suggestion is supported by a comparison between published data of the SEE yield δ°o f insulators (short pulse experiments) and experimental results obtained from a permanent irradiation for E C 2 . New SEE effects are also predicted at the early beginning of irradiation when finely focused probes are used. Practical considerations are also developed, with specific attention given to the role of a contamination layer where a negative charging may occur at any beam energy. The role of the various time constants involved in charging and discharging is also investigated, with special attention given to the dielectric time constant, which explains the dose rate-dependent effects on the effective landing energy in the steady state. Numerical applications permit to give orders of magnitude of various effects, and several other practical consequences are deduced and illustrated. Some new mechanisms for the contrast reversal during irradiation or with the change of the primary electron (PE) energy are also suggested.

show abstract

Section: Experimental Supportmentioning

confidence: 99%

Charging in scanning electron microscopy “from inside and outside”

Cazaux¹

2004

Scanning

View full text Add to dashboard Cite

show abstract

“…This is directly related to the well accepted idea that trapping in insulator is due to defects. In inorganic materials such as ceramic, the variation of polarisability is coming from point and extended defects such as vacancies [46], segregation, grain boundaries [47]...For crystalline polymers, the structural defects are so numerous that they give a quasi continuous distribution of polaron traps. This approach of the conduction proposed by Blaise [45,48] differs from the more classical one [49], because it does not involve exchange of electron or hole between the rigid band structure and discrete levels localised in the band gap.…”

Section: Figure 4 : Illustration Of the Band Diagram Related To The Cmentioning

confidence: 99%

Electrical charges and tribology of insulating materials

Guerret‐Piécourt¹,

Bec²,

Tréheux³

2001

Comptes Rendus de l'Académie des Sciences - Series IV - Physics

View full text Add to dashboard Cite

Résumé. La description de la génération de charges électriques lors du contact entre isolants a été faite de longue date. En revanche, la prise en compte quantitative des effets de ces charges est rarement évoquée dans les bilans énergétiques concernant les problèmes de frottement. En nous appuyant sur des résultats publiés et sur nos propres expérimentations sur le piégeage des charges dans les isolants, nous montrons l'importance de l'action de ces charges électriques sur l'énergie d'interaction pendant le frottement. Enfin, nous proposons d'évaluer quantitativement cette contribution grâce à l'utilisation complémentaire de la méthode « miroir » et de mesures de forces de surfaces. caractérisation diélectrique / frottement / triboélectrification / interactions interfaciales / énergie libre de surface / charge d'espace / forces de surface Abstract. Electrical charges generation occurring during contact and friction of insulating materials has been identified for a long time. However the contribution of these electrical charges to the friction behaviour is usually neglected in the energetical balances. Based on published results and on our own experimental results on the ability of the dielectric materials to trap charges, we show in this study that the interaction energy during friction depends markedly on these trapped charges. Eventually, we propose the complementary use of the "mirror " method and of surface forces measurements to obtain a quantitative evaluation of this contribution. dielectric behaviour / friction / triboelectrification / interfacial interactions / surface free energy / space charge / surface forces IntroductionSurface forces act between two surfaces when they are in close proximity. They are very well known in the field of colloid science [1, 2] and they have also a strong impact in other fields like adhesion, wetting or friction. Resulting from very complex phenomena, these forces include mechanical, physico-chemical and electrical effects. This paper is focused on one phenomenon which is often neglected : the effects of electrical charges trapped in the near surface or in the bulk of dielectric materials (ceramics, polymers...). In section 2, the various types of surface forces according to their range are recalled. Then, it is shown that some published results in the friction and adhesion domains suggest the major role of these electrical charges. This is followed by an overview on charge generation and trapping during contact or friction in section 3. Our own results are used in section 4 to discuss how electrical charges can influence the friction behaviour of dielectrics. In order to go further, the complementary use of the "mirror " method and of surface forces measurements is proposed in the aim to obtain a quantitative evaluation of this contribution.

show abstract

“…The ICM method is based on the measurement of the current I ind , produced by the variation of the induced charges Q ind (in the sample holder) due to the trapped charges in the sample Q t (Liebault et al, 2001Song et al, 1996). Since the influence coefficient in our experimental set up is close to one (Zarbout et al, 2008), the amount of the net trapped charges is given by:…”

Section: The Improved Induced Current Measurement Methodsmentioning

confidence: 99%

“…The dielectric properties of undoped corundum, α-alumina, of different kinds (single crystal or polycrystalline obtained by solid state sintering) have been the subject of numerous studies concerning, in particular, the breakdown strength and the charging behavior (Haddour et al, 2009;Liebault et al, 2001;Si Ahmed et al, 2005;Suharyanto et al, 2006;Thome et al, 2004;Touzin et al, 2010;Zarbout et al, 2008Zarbout et al, , 2010. The common feature pointed out by most of these investigations is the conspicuous role played by the microstructure and the impurities.…”

Section: Introductionmentioning

confidence: 99%

“…This parameter is intimately linked to the charging properties as breakdown originates from the enhancement of the density of trapped charges, which stems from the competition between charge trapping and conduction Le Gressus et al, 1991;Liebault et al, 2001;Haddour et al, 2009). The charges can be either generated by irradiation or injected through interfaces via an applied voltage.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation