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Nickel hydroxide electrodes prepared by chemical and electrochemical impregnation (CI and EI) have different crystal structures due in part to the amount of water in the active materials false[β‐normalor α‐normalNi false(OH)2false] . In order to understand the relationship between the structure and the water content, for the EI electrode, x‐ray diffraction (XRD) and thermogravimetric analysis (TGA) were used. TGA of CI and EI electrodes in air, nitrogen, and vacuum revealed that there are two types of chemical reactions which take place in the electrode material, one due to dehydration and the other due to decomposition of hydroxide to oxide. The dehydration of EI electrode active material also resulted in a decrease of the “c” spacing of the unit cell due to water removal from planes perpendicular to the “c” axis of nickel hydroxide crystals.

A series of transparent homogeneous amorphous solids between Ge02 and GeO has been prepared by rapid quenching of liquids and by vapour deposition. Density and refractive index increase smoothly with increasing Ge/O ratio and provide a useful index of composition. Glasses in the range GeO-GeOlS8, undergo a rapid exothermic transformation when heated above 400°C accompanied by a pronounced blackening, an increase in refractive index, and a slight decrease in density. Electron microscopy and diffraction results indicate that the transformation invohes the precipitation on a 50-100 A scale of an amorphous tetrahedrally coordinated Ge-rich phase. The interconnected microstructure so produced is suggestive of spinodal decomposition. A transitional region near GeOlS9 is characterized by sluggish phase separation kinetics and a dispersed particle morphology suggestive of a nucleation and growth precipitation mechanism. Glasses in the range GeOl.9-Ge02 show no evidence for phase separation.