A saffron-coloured crystal could provide a step towards greener electronics.
Some types of low-power computer memory store information using metals that are ferroelectric, meaning they form positive and negative poles when placed in an electric field. However, many of the more common metals used are either rare or toxic.
Now at the National Institute of Advanced Industrial Science and Technology in Ibaraki, Japan, and colleagues have discovered ferroelectric behaviour in crystalline croconic acid, which contains just carbon, oxygen and hydrogen.
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Croconic acid was discovered 170 years ago but crystallised for the first time within the past decade. When Horiuchi鈥檚 team applied an electric field to the crystals at room temperature they could reverse its electric polarity.
The researchers noticed a small time lag between removing the field and reversal of the crystal鈥檚 polarity. This is 鈥渢ypical of ferroelectrics鈥�, says Horiuchi, and a 鈥渄irect indication of the ability to store and switch an electrical polarisation鈥�. The finding suggests croconic acid could be used in organic electronics.
at Queen鈥檚 University Belfast, UK, says that there already exist some organic polymers with ferroelectric properties, including polyvinylidene fluoride. 鈥淸But] the availability of more organic ferroelectric systems than the PVDF-like systems is pretty cool, as it opens up more opportunities for all organic devices than had previously been available.鈥�
Although he points out that the Horiuchi team鈥檚 results suggest croconic acid might switch polarity too sluggishly for use in ferroelectric RAM, 鈥渢he work will, I think, nevertheless be received with some excitement鈥�.
Journal reference: , DOI: 10.1038/nature08731
