Diphasic Xerogels, A New Class of Materials: Phases in the System Al ₂ o ₃ ‐Sio ₂

Two series of xerogels (desiccated hydrogels), one consisting of single phases and the other of two phases, were prepared from organic and inorganic precursors in the system Al ₂ o ₃ ‐Sio ₂ . The effect of these nanostructural differences in the xerogel powders on the energy content and behavior on heating were studied using DTA, powder X‐ray diffraction, and ultrafast heating on a strip furnace. The results demonstrate that diphasic xerogels are substantially different materials from single‐phase xerogels of the same composition.