Controlling the morphology of amorphous solid water

The morphology of amorphous solid water grown by vapor deposition was found to depend strongly on the angular distribution of the water molecules inci dent from the gas phase. Systematic variation of the incident angle during deposition using a collimated beam of water led to the growth of nonporous to highly porous amorphous solid water. The physical and chemical propertie s of amorphous solid water are of interest because of its presence in astro physical environments. The ability to control its properties in the laborat ory may shed light on some of the outstanding conflicts related to this imp ortant material.