Advantage of pseudo-binary PhaseChange material against eutectic material for application in poor rapid cooling structure

In PhaseChange (PC) commercial disks, the PC material is used with a thick reflector which also acts as a highly efficient heat sink providing that the stack is well tuned regarding heat flow properties. In this case, growth dominated materials based on the eutectic composition Sb/sub 70/Te/sub 30/ are good candidates (Zhou-GF et al, Proc. SPIE vol. 4090, pp. 108-115, 2000). However in some structures where a highly efficient heat sink is no longer possible, GeSbTe-based materials (nucleation dominated behaviour) could show higher potentiality. This situation can be faced in dual level disks for example, as we show here.