Abstract: In data-storage media such as rewritable optical discs (DVD−RAM, DVD+RW, DVD−RW, DVR, CD−RW and PD), the current need for the disc to be initialised before it can be used is eliminated. This is achieved by depositing on the disc, immediately before and/or after the record layer itself has been deposited, a layer of additional material that induces the record layer to become deposited in its crystalline state, or to be transformed spontaneously into that state. One specific material, which has this effect on record layers of GeSbTe and/or AgInSbTe, is Sb2Te3.