The availability of optical disk memory with archive lifetimes will require either metal films that oxidize very little, or else transparent barrier coatings that will block oxygen transport. Polymers transmit both water vapor and oxygen. Ion beam deposited Diamond-Like Carbon films are expected to provide a hermetic, oxygen barrier coating to extend the lifetime of optical disks.
"Novel Materials For Improved Optical Disk Lifetime", Proc. SPIE 0299, Advances in Laser Scanning Technology, (26 April 1982); doi: 10.1117/12.932555; https://doi.org/10.1117/12.932555