Minimal Phase-Change Marks Produced in Amorphous Ge2Sb2Te5 Films

The smallest mark which can be produced in phase-change recordings has been explored using an atomic force microscope. Electrical pulses applied to amorphous Ge2Sb2Te5 films through conducting cantilevers can produce crystalline marks, the size decreasing with decreases in input power, pulse duration, and film thickness. The smallest mark obtained is ~10 nm in diameter in a film with thickness of ~1 nm. Formation mechanism of the mark is discussed.