The lamellar spacing changes among microstructural parameters of any two eutectic phases are related to their entropies of fusion. An immense systematic series of investigation and observation thereof, predicts the terminal nature of both transparent and opaque binary eutectic systems. Experimental evidences are obtained for theoretical shapes of the lamellar solidus-liquidus interfaces, for the movement of lamellar-faults and for the development of low-energy solidus-solidus boundaries between the lamellae. A comprehensive explanation is presented to account for the regular, irregular and complex regular structures which are found in an experimental series of eutectic systems. In the domain of present probe, an important evidence is obtained that reflects the lamellar eutectic structure to be less regular compared to rod eutectic structure.
