As is well known, melts that have passed a miscibility gap in the liqu
id state will, on cooling, solidify to a regulus consisting of two lay
ers. Such bodies are not interesting for technical applications and ha
ve rarely been investigated. Genuine interest in demixing systems only
arose once it seemed possible to prevent layer formation in zero grav
ity. However, experiments in space have shown that, even under micro-g
conditions, phase separation occurs, though in a different way than o
n earth. This resulted in an intensive disclosure of the thermodynamic
s and the kinetics of the separation of liquid immiscible phases. Afte
r a discussion of the results obtained, the paper suggests how to prev
ent layer formation and how to effect a finely dispersed structure to
enable technical use.