I am involved in the design and test of low-pressure, mercury vapor lamps for the air and water purification industry. Many lamps contain an indium/mercury amalgam to extend the high-temperature operational range.
After several on/off cycles we notice spicules/spikes/dendritic structures growing up from the applied amalgam. They don't affect the lamp's operation since they melt back when the lamp is on, but what actually causes them? The closest analogue I have yet found is the growth of ice spicules from ice made out of distilled water. Is this an analogous process? Is there any published work you can point me to. In this case Google wasn't to much of a friend.
WEL