Titanium oxide used for 5nm optical storage

Super disks could be 1,000 times bigger than Blu-Ray

A Japanese research team has discovered that titanium oxide - a material most commonly used in white paint and sunscreen, of all things - could be used in future optical storage disks.

Boffins at the University of Tokyo said that the material could be used to make low-price 'Super Disks' with a storage capacity thousands of times greater than DVD.

The material, which is a new crystalline form of titanium oxide, switches between metal and semiconductor states when exposed to light at room temperature effectively creating an I/O state which is repeatedly reversible.

The team has successfully created the material in tiny particles measuring as little as five nanometers which would give standard-sized disks a theoretical storage capacity a thousand times greater than Blu-ray.

Add to that the fact that titanium oxide is currently about 100 times cheaper than germanium-antimony-tellurium - the stuff that makes current optical storage disks so expensive - and you can see why the Tokyo team is getting so excited.

Head boffin, Prof. Shin-ichi Ohkoshi is currently talking to private companies about commercialising the project, but titanium oxide Super Disks are unlikely to make it to market for at least a few years - if ever.

Anyone with a giant brain or a degree in chemistry might be interested in the following:

Photoinduced phase-transition materials, such as chalcogenides, spin-crossover complexes, photochromic organic compounds and charge-transfer materials, are of interest because of their application to optical data storage.

Here we report a photoreversible metal–semiconductor phase transition at room temperature with a unique phase of Ti3O5, λ-Ti3O5. λ-Ti3O5 nanocrystals are made by the combination of reverse-micelle and sol–gel techniques. Thermodynamic analysis suggests that the photoinduced phase transition originates from a particular state of λ-Ti3O5 trapped at a thermodynamic local energy minimum.

Light irradiation causes reversible switching between this trapped state (λ-Ti3O5) and the other energy-minimum state (β-Ti3O5), both of which are persistent phases. This is the first demonstration of a photorewritable phenomenon at room temperature in a metal oxide.

λ-Ti3O5 satisfies the operation conditions required for a practical optical storage system (operational temperature, writing data by short wavelength light and the appropriate threshold laser power).

Simple, innit?