PERIODIC PRECIPITATION (LIESEGANG PHENOMENON) IN SOLID SILVER .2. MODIFICATION OF WAGNERS MATHEMATICAL ANALYSIS

In the previous paper(1) an experimental study of Lieaegang precipitation in solid silver (Ag-H2O experiment) was described. Single crystals of silver were annealed at 800°C in some partial pressure of oxygen to saturation and were then annealed in a partial pressure of hydrogen. Hydrogen diffused into the silver and reacted with the dissolved oxygen to form water vapor bubbles which under certain conditions formed in bands obeying Jablczynski's relationship. Carl Wagner's mathematical analysis of periodic precipitation has been modified, and when the spacing coefficients calculated with this theory were compared with those found experimentally, the agreement was satisfactory with one exception. It was found that the variation of the spacing coefficient with the variation of the oxygen concentration predicted by theory was opposite to the variation observed. Some suggestions have been advanced for this discrepancy, and it has been shown how some previous results in other systems can be explained by the modified Wagner analysis. © 1969.