Researchers from the University of Twente have created a storage medium that is touted to last a million years. The disk is able to store data reliably over such a long period of time primarily due to the use of tungsten as its construct material.
The researchers had to deal with the issue of data corruption and had to come up with a solution to overcome the effects of time on stored data. The researchers also pointed out that while magnetic data storage is suitable for current usage, its "energy barrier" is insufficient to survive a million years. Hence, in order to create a storage medium to last that long, its energy barrier has to be high enough to guard against erasure. As noted by Technology Review, the idea of energy barrier falls under the Arrhenius law, and calculations have shown that an energy barrier of 63kBT or 70kBT is required to make the data last a million years.
With that in mind, the researchers, from the Institute for Nanotechnology of the university, went ahead to create such a storage medium. A thin metal disk is created from tungsten, and the data is etched onto the disk. After that, a protective layer is applied on the metal disk. The researchers chose tungsten due to its "high melting temperature (3,422 degrees C) and low thermal expansion coefficient." The protective material is silicon nitride (Si3N4) and it is chosen due to its "high resistance to fracture and its low thermal expansion coefficient."
The researchers managed to etch data representing a QR code onto the disk and the data has to be read through an electron microscope. They also subjected the disk to a thermal stress test and discovered that it couldn't withstand temperatures beyond 172 degrees Celsius (445 Kelvin). Hence, we do foresee that this storage technology will take some time before it becomes commercially viable. In the meantime, end-consumers may want to consider the M-Disc, a 1000-year optical storage disc, for their data archival requirements.