Crosslinking polymers may be used as negative acting resists. The product of the minimum charge dose Q required and the weight average molecular weight Mw is a constant and is a characteristic of the polymer. At an electron beam voltage of 10 kV, this Q-M product is found experimentally to be 9 .3 coul-g/cm2-mole for polystyrene, 1 coul-g/cm2-mole for poly(vinyl chloride), and 14 coul-g/cmS-mole for polyacrylamide. Degrading polymers may be used as positive acting resists. Their average molecular weights have only a very minor effect on their efficiency as positive resists. Their glass transition temperatures T a are an important factor. It is recommended that these resists be prebaked at T > Tg, stored and developed at T < Tg, and postbaked at T > Tg.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.22.67.16
ABSTRACTThe synthesis of terbium-activated compounds in Ln203-SiO2 system is described and their cathodoluminescence is compared to Zn2SiO4:Mn, (ZnCd)S:Ag, and other efficient Tb+S-activated phosphors. The utility of the Tb +3 phosphors in tricolor CR tubes is also considered.
SynopsisThe yield and quality of an electrophoretically deposited polyimide are strongly dependent upon a number of parameters that are closely related to the formulation and characteristics of a basic nonaqueous electrophoretic emulsion. Such parameters, which have been optimized for one specific polyimide, are solvent/precipitant ratio, type and concentration of surfactant, emulsion preparation sequence, apparent pH, and solids content.
Barium and calcium stearate Langmuir films from 1 to 10 monolayers in thickness (approximately 25–250Aå) have been investigated for use as ultrathin insulating barriers between evaporated metal electrodes. These metal‐insulator‐metal sandwiches showed highly nonlinear and temperature dependent conduction characteristics, from which a thermal barrier height of 0.25–0.30 ev is calculated. Reproducibility of electrical properties however was poor, apparently due to voids and inhomogeneities in the organic insulating films. It is calculated that even in the best samples, 2 to 3 monolayers were required to eliminate voids penetrating completely through the organic films. A reactive and hence oxidized surface was found to be necessary for the formation and retention of low porosity layers, tin being the most successful substrate electrode material. Insulating behavior could not be obtained from films transferred onto gold electrodes. Film structure and adhesion was investigated by studying the layering process and the autoradiographs obtained from C14 tagged films. The autoradiographs did not reveal any significant defects in the layers down to the resolution of the negatives (∼25μ). It was found that the physicochemical nature of the substrate surface affected the adhesion of more than the first monolayer, and that porosity alone was unlikely to account for the long‐range effect. Positive ion adsorption, as described by Goranson and Zisman, is suggested as a possible alternative and shown to be consistent with some aspects of the electrical measurements.
SynopsisAromatic polyamides and polyimidea of high molecular weight are currently under development by many industrial laboratories. Wire enamels, laminating and impregnating resins, and varnishes incorporating this new clrtss of thermally stable polymers withstand higher operational temperatures than do most organic polymeric materials in use today. The thermal and oxidative stability of two of these resins has been investigated in air, in oxygen, and in 0'8-enriched oxygen over a temperature range of 300-400'C. The mechanism of degradation is postulated to be that of a unit by unit destruction of the polymer.
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