Electronic memory

The authors thank Drs. T. Tamura, K. Yamamoto, and Y. Banno for helpful suggestions and technical assistance. This work was supported by grants from Teimei Empress Memorial Foundation, the Futaba Electronics Memorial Foundation, and Grant-in-Aid for Scientific Research of Japan Society for the Promotion of Science. 

Accumulation and reorganization of information can also be achieved on the basis of cis-trans isomerization of olefins in their ion-radical states. An application of the phenomenon in real electron memory systems was claimed (Todres 2001). For the neutral arylethylenes, conversion from... 

Exploiting arylethylenes as bearers of electron memory has the following advantages First, the compounds are commercially available and inexpensive. Second, they work for very long time. Third, transformation of the information recorded is simple and consumes little energy. In other words, creation of electron memory systems through ion-radical route is fruitful. 

Green, J. E., Choi, J. W., Boukai, A., etal, A 160-kilobit molecular electronic memory patterned at 10" bits per square centimetre. Nature 2007, 445, 414-417. 

Ferroelectric ceramics (such as barium titanate, lead zircanate titanate) Sensors and actuators, electronic memory, optical applications Tape casting, sputtering, pressing, templated grain growth Improved dielectric and piezoelectric properties... 

Fig. 33 A 160-kb molecular electronic memory device [236]. (a) Structural formula of the molecular switches used in the device.

The notion of using molecules as storage centers for electronic memory is seductive. Use of molecules in memory clearly allows for extraordinary miniaturization, thereby permitting a high density of information storage. Because of their capacity to store multiple electrons (bits) and to exhibit diverse stereochemistries, metal complexes are of particular interest. One feature needed for a practical molecular memory is the ability of the redox functionahty to sustain multiple read-write cycles, that is, to withstand multiple oxidations and reductions without decomposition. Such a consideration is a concern for metal complexes that are typically more stable in one redox form compared to the others. 

Mass data storage represents something of a problem. Floppy discs are probably inadvisable under the severe conditions at sea (vibration, large motion, dirty air, etc.). Some forms of data storage that do appear desirable are Winchester discs (if head crashes can be avoided), digital tape recorders, electronic memory systems (protected from power interruptions), or bubble memories (a bubble memory for the Apple II has become available commercially). 

K. Yano et al., Room temperature single electron memory, IEEE Trans. Electron. Dev. 41, 1628 (1994). 

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