Nano-particles may help compress computer memory

Brown University chemists have devised a simple way to synthesize iron-platinum nanorods and nonowires while controlling their size and composition.

Washington, June 24 : Brown University chemists have devised a simple way to synthesize iron-platinum nanorods and nonowires while controlling their size and composition.

The new technique attains importance because scientists have always found difficulty to make in bulk nanorods with uniform shape and magnetic alignment, which are deemed a key to the next generation of high-density information storage.

Published online in the journal Angewandte Chemie International Edition, the technique produces nanorods and nanowires from 20 nm to 200 nm long, simply by varying the ratio of solvent and surfactant used in synthesis.

Chemistry professor Shouheng Sun and postdoctoral researcher Yanglong Hou have also demonstrated that the same technique works to control the shape of cobalt-platinum nanorods, suggesting that it may work for many other combinations as well.

Both researchers believe that they can harness particle shape to accomplish the critical task of compressing computer memory.

"Many people think that shape can control alignment, but controlling shape has not been so easy. This method gives us a really simple way to tune length, diameter and composition all at the same time," said Professor Sun

According to Professor Sun and Hou, the method developed by them produces batches of similarly sized nanowires or nanorods in solution.

The researchers say that including more surfactant (oleylamine) in the reaction mixture produced longer wires, and that more solvent (octadecene) gave shorter rods. A three-to-one ratio of surfactant to solvent yielded 100 nm wires, while a one-to-one ratio produced 20 nm rods, they say.

The researchers believe that the surfactant molecules create protective tunnels around the growing nano-rods, guiding them into longer, rather than thicker shapes. They also say that the surfactant molecules line up with water-loving tails inward and water-repellant heads out.

With more surfactant in the solution, the tunnels grow longer before solvent molecules interrupt the pattern.

The researchers say that the method also has great potential in other areas where very dense magnetic charge is an advantage, such as magnetic motors and generators.

They say that the stability and biocompatibility of the iron-platinum alloy also make such nanorods and nanowires good candi-dates for biological applications.

ANI