Cuneiform Of The Future Or Memory Retains Seignette-Electrics

Chips based on Seignette-electrics (ferroelectrics) will retain recorded information for centuries, this being done without any power replenishment. Devices based on these wonderful materials’ thin films will help to track the route of an animal or a bird during its overall life span, to control the valuable freight travel and to find the lost or stolen stuff, even if more than a year elapsed since the time of a loss. The information on the St. Petersburg researchers’ development is available in the Internet – in the section of advanced research of the International Science and Technology Center database.

Neither paper nor leather but clay tablets with stroke symbols and pictures drawn on them have preserved for descendants biographies of tzars of the past and lovers’ notes of the same period. Probably in the future, the long-term repositories will be also based on ceramics layers. Certainly, these will be very thin layers and very special ceramics. The materials are called Seignette-electrics (ferroelectrics) following I.V. Kurchatov’s example – it is him who invented this name in honour of a French pharmaceutical chemist E.Seignette, who was the first to pay attention to unusual properties of one of the tartaric acid salts.

The point is that Seignette-electrics’ crystals consist of domains with different directions of polarization – as if a multitude of crystalline aciculae in the shape of a figure formed by two pyramids whose foundations are put together. And low-level cells of the crystals, of which the domains consist, are slightly asymmetrical – in some low-level cells their, figuratively speaking, ‘centre of electric gravity’ is shifted towards one side, and in other cells – towards the opposite side.

It is important that upon changing external conditions – temperature, electric field or mechanical stress these domains can grow up, i.e. their area may increase and remain like that – until they are affected again. If ‘plus’ is applied – domains of one orientation will grow up, if ‘minus’ is applied – the area of other domains will increase. Along with that, characteristics of the entire crystal will change, in particular – remanent polarization that depends on its domains orientation. Hence, there is a possibility to record and keep the data. Most importantly, retaining the information does not require any additional power. Theoretically it is possible to make nonvolatile memory with high speed of operation, such memory being very reliable even in the conditions of ionizing radiation

However, since the time of its discovery and so far the properties of the Seignette salt and its multiple relatives have not only been studied but also extensively utilized – they have been used as a basis to produce ceramic capacitors and elements of microwave equipment, ultrasonic vibrations oscillators and receivers, infrared emission receivers and multiple useful things in general (only production of capacitors based on Seignette-electrics accounts for several billion units per year worldwide), memory elements based on them are only beginning to emerge. The problem is that scientists should learn how to produce these memory elements for contemporary processors by applying the methods compatible with the integrated all-solid state circuitry production techniques.

Specialists of the legendary Ioffe Physical & Engineering Institute (followers of the founders of the Seignette-electrics science – Academicians A.F. Ioffe and I.V. Kurchatov) have learned to grow up thin-film structures from Seignette-electrics for creation of nonvolatile memory. They have obtained the metal-Seignette-electric-metal and metal-Seignette-electric-semiconductor thin-film structures required for memory cells. These are microscopic capacitors of several microns in diameter – i.e., sections of a thin Seignette-electric film (its thickness being hundredths fraction of a micron) are between two electrodes. The quality of these films allows to hope that the chips based on them will operate quickly, efficiently and for a long time.

The researchers have not developed yet manufacturing technologies for production of such films – additional funding is needed. However, experts of the International Science and Technology Center have placed the information about this project on its site – in the section of advanced technologies. Therefore, such Seignette-electric memory will probably retain information for descendants. Besides, small radio frequency identifiers may be based on such memory cells intended for commodities, cellular phones and, for instance, cranes to track their migration anywhere and as long as required. The memory will be nonvolatile one, so there will be no need to worry about a battery running out.