InSbTe phase-change materials for high performance multi-level recording

Eutectic-based InSbTe phase-change materials have been developed for low sigma-to-dynamic range (SDR) multi-level (ML) performance at linear track velocities (LTVs) of 1.9 m/s to 6 m/s. Compositions with the stoichiometry In-x(Sb72Te28)(100-x) (3.9 < x < 45) were tested. Compositions that achieved low SDRs did so at 1.9 m/s, 3.5 m/s and 6 m/s. We found two minima in the SDR at concentrations of x = 10% and x = 30% indium. We explain this unique finding through write-erase characteristics and crystal structure. At indium concentrations lower than 10% and higher than 30%, the favored rhombohedral crystal structure was not the major phase formed, and the SDR increased. The minima in SDR at 10% and 30%, in conjunction with a maximum at 20%, can be explained by fast solid-state crystallization time and slow,melt recrystallization time.