By Nick Gilbert
Organic chemists at the Northwestern University have engineered a new class of organic materials that demonstrate the desirable property of ferroelectricity in addition to possessing exceptional memory.
Ferroelectric materials are electrically polarized wherein one end of the material is negatively charged and the other end is positively charged. The polarization can be reversed by applying an external electric field. The ability to demonstrate two such orientations make ferroelectric materials ideal candidates for computer memory, which require two memory states to represent the binary digits of 1 and 0. Existing ferroelectrics are however expensive and difficult to produce as they are obtained from special types of ceramics and polymers.
The team at Northwestern used two molecules from simple, inexpensive compounds with great affinity towards one other to form long crystals with ferroelectric properties. The properties of the new material are attributed to the persistent affinity between the base molecules leading to constant interactions and are not the result of the molecules themselves. The interactions are ordered and give rise to strong hydrogen bonds. It is these ordered bonds that set the premise for ferroelectricity.
Though such interaction between two molecules paving the way for ferroelectricity has been observed in three other materials, the phenomenon was observed only under temperature conditions below that of liquid nitrogen. The material developed at Northwestern undergoes such interactions at room temperature. The new material could be a cost-effective alternative for conventional non-volatile memories and can replace volatile memories employed in cloud computing.