Electron resists

In an aqueous electrolyte, the anodic behaviour of lead vanes greatly depending on the conditions prevailing. Extensive reviews of the anodic behaviour of lead have been produced Under certain conditions, the passive film may be converted to lead dioxide which has an electronic resistivity of 1 - 4 x 10" Ohm cm. Two polymorphs of PbO, exist, a and... 

In its general corrosion behaviour, beryllium exhibits characteristics very similar to those of aluminium. Like aluminium, the film-free metal is highly active and readily attacked in many environments. Beryllium oxide, however, like alumina, is, a very stable compound (standard free energy of formation = —579kJ/mol), with a bulk density of 3-025g/cm as compared with 1 -85 g/cm for the pure metal, and with a high electronic resistivity of about 10 flcm at 0°C. In fact, when formed, the oxide confers the same type of spurious nobility on beryllium as is found, for example, with aluminium, titanium and zirconium. 

Electronic conductivity of thin-film solid electrolytes. Besides having low electronic transference numbers, it is essential for thin films of the order of 1 jim that the magnitude of the electronic resistance is low in order to prevent self-discharge of the battery. For this reason, specific electronic resistances in the range of 1012-1014 Qcm are required for thin-film solid electrolytes. Often the color may be a valuable indication of the electronic conductivity. In this regard, solid electrolytes should preferably be transparent white [20]. 

In solid-state batteries, it is extremely favorable to use the solid electrolyte for mechanical support. Despite the larger thickness, which lowers the relative amount for active material in the battery, the advantages are the absence of pinholes of the solid electrolyte, high electronic resistance, and simple multistack fabrication, since the individual cells may be contacted by their electronically conducting current collectors. 

Compared with the ionic conductivity of p" —alumina tubes, the electronic conductivity is negligible. The electronic resistivity was found to be 109Qcm at 300 °C and 7x lO3 Qcm at 1000 °C [27]. 

Impedance spectroscopy is best suited for the measurement of electronic conductivities in the range 10 -7to 10 2S cm 1.145 In principle, it is perhaps the best method for this range, but it is often difficult to interpret impedance data for conducting polymer films. The charge-transfer resistance can make measurements of bulk film resistances inaccurate,145 and it is often difficult to distinguish between the film s ionic and electronic resistances.144 This is even more of a problem with chronoamperometry146 and chronopotentiometry,147 so that these methods are best avoided. 

Figure 10. Cyclic voltammetry (top) and in situ electronic resistance (bottom) of poly(3-methylthiophene) from parallel-band electrode [Fig. 9(A)] experiments in S02(1) containing 0.1 M Bu4NPF6.37 (Reprinted with permission from J. Am. Chem. Soc. 112, 7869-7879, 1990. Copyright 1990, American Chemical Society.)...

Figure 15 shows a set of complex plane impedance plots for polypyr-rolein NaC104(aq).170 These data sets are all relatively simple because the electronic resistance of the film and the charge-transfer resistance are both negligible relative to the uncompensated solution resistance (Rs) and the film s ionic resistance (Rj). They can be approximated quite well by the transmission line circuit shown in Fig. 16, which can represent a variety of physical/chemical/morphological cases from redox polymers171 to porous electrodes.172... 

From an analysis of data for polypyrrole, Albery and Mount concluded that the high-frequency semicircle was indeed due to the electron-transfer resistance.203 We have confirmed this using a polystyrene sulfonate-doped polypyrrole with known ion and electron-transport resistances.145 The charge-transfer resistance was found to decrease exponentially with increasing potential, in parallel with the decreasing electronic resistance. The slope of 60 mV/decade indicates a Nemstian response at low doping levels. 

The relatively high volatility of Tg[CH = CH2]8 has enabled it to be used as a CVD precursor for the preparation of thin films that can be converted by either argon or nitrogen plasma into amorphous siloxane polymer films having useful dielectric propertiesThe high volatility also allows deposition of Tg[CH = CH2]g onto surfaces for use as an electron resist and the thin solid films formed by evaporation may also be converted into amorphous siloxane dielectric films via plasma treatment. ... 

Strategies towards optimization of the cathode structure consist of improving the removal of water, lowering the ionic and electronic resistance, and preventing the deposition of platinum in inaccessible catalyst pores. 

We first met the concept of IR drop in Chapter 3 (Section 3.6.4). IR drop is also a cause of error in dynamic electroanalysis. The analyte solution has an electronic resistance of R, and a potential E is applied between the reference and working electrodes, so an additional current I is induced. The magnitude of such an ohmic current / is E/R, according to Ohm s law (equation (2.2)). 

Saab, A. P, Garzon, E. H., and Zawodzinski, T. A. Determination of ionic and electronic resistivities in carbon/polyelectrolyte fuel cell composite electrodes. Journal of the Electrochemical Society 2002 149 A1541-A1546. 

Figure 14. Current distribution in a straight-channel fuel cell at a cell voltage of 0.6 V (a) without GDL electronic resistance and (b) with GDL electronic resistance.

Figure 30. Exposure curves for COP negative electron resist on three substrate materials.

Figure 2. A sensitivity diagram showing the exposure window for electron resists.

Figure 4. Typical response or sensitivity curve for a negative electron resist. The value of Dg is obtained from Figure 3 and usually occurs at 0.5 - 0.7 normalized thickness.

Figure 5. Typical sensitivity or response curve for a positive electron resist. Positive resist response may also be plotted using other conventions (see...

Figure 21. Scanning electron beam micrographs of COP negative electron resist patterns developed in two different ketone-alcohol mixtures.

A Sensitive Positive-Working Cross-Linked Methacrylate Electron Resist... 

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