Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New nano-method may help compress computer memory

Simply changing the ratio of two chemicals in solution changes the length of iron-platinum nanowires and nanorods: transmission electron microscope images of a) 200 nm wires; b) 50 nm wires; c) 20 nm rods; d) two individual 50 nm wires.

Credit: Chao Wang & Jaemin Kim/Brown University
Simply changing the ratio of two chemicals in solution changes the length of iron-platinum nanowires and nanorods: transmission electron microscope images of a) 200 nm wires; b) 50 nm wires; c) 20 nm rods; d) two individual 50 nm wires.

Credit: Chao Wang & Jaemin Kim/Brown University

Abstract:
A team of chemists at Brown University have devised a simple way to synthesize iron-platinum nanorods and nanowires while controlling both size and composition. Nanorods with uniform shape and magnetic alignment are one key to the next generation of high-density information storage, but have been difficult to make in bulk.

New nano-method may help compress computer memory

Providence, RI | Posted on June 22nd, 2007

The technique, published online June 22 in the journal Angewandte Chemie International Edition, pro-duces nanorods and nanowires from 20 nm to 200 nm long, simply by varying the ratio of sol-vent and surfactant used in synthesis. Shouheng Sun, a professor of chemistry at Brown Univer-sity, postdoctoral researcher Yanglong Hou, and colleagues 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.

Just a few years ago, the average computer user's documents, applications and even photos seemed to rattle around a 120 GB disk drive. Today's multimedia-intensive user can exhaust that capacity in no time and the need continues to grow, but engineers expect to max out conven-tional magnetic storage techniques by about 2010. At that point, they'll be looking for nanotech-nology to step up. Whether it will be ready, remains to be seen.

Getting tiny magnetic particles to align with each other has been one of the major obstacles to squeezing more information density out of the technology. Sun and Hou think they can harness particle shape to accomplish that critical task.

"Many people think that shape can control alignment," said Sun, "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."

A magnetic storage surface - the disk of a hard-disk drive -- consists of tiny sectors of magneti-cally-aligned particles. When the read-write head of a disk drive passes over a sector, it flips the magnetic field to the opposite direction - encoding a zero or a one. When it reads, it senses the magnetic field for the whole sector. To pack more information into a smaller area, engineers can make the particles smaller or the sectors smaller, but they need enough particles so that the occa-sional random flip doesn't corrupt the whole sector.

It is now possible to apply magnetic nanoparticles in a thin, dense layer, but the magnetic fields of randomly-oriented spherical particles tend to cancel each other out. Instead of lining up at six o'clock or twelve o'clock, many particles align at two, three, four or five o'clock, diluting the overall strength of the magnetic signal.

Long, narrow nanorods could pack alongside each other, with their magnetic fields oriented in only two directions. Imagine a plate covered with Good and Plenty's rather than fireballs. The elongated candies line up side-by-side, while the balls role around randomly. Nanorods, aligned in the same direction, should produce a stronger signal and switch cleanly from zero to one and vice versa.

The method developed by Sun, Hou, and graduate students Chao Wang and Jaemin Kim pro-duces batches of similarly-sized nanowires or nanorods in solution. The researchers found 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.

Based on this pattern, plus transmission electron microscope and x-ray diffraction images, the researchers think that surfactant molecules create protective tunnels around the growing nano-rods, guiding them into longer, rather than thicker shapes. The surfactant molecules line up with water-loving tails inward and water-repellant heads out. With more surfactant in the solution, the tunnels (and the nanorods inside) grow longer before solvent molecules interrupt the pattern.

In addition to information storage, the method has great potential in other areas where very dense magnetic charge is an advantage, including magnetic motors and generators. The stability and biocompatibility of the iron-platinum alloy also make such nanorods and nanowires good candi-dates for biological applications.

The National Science Foundation (NSF), Information Storage Industry Consortium (INSIC), and the Office of Naval Research all contributed funding for this project. Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call 410-863-2476.

####

About Brown University
Approximately 5,900 students are enrolled in the Undergraduate College, 1,500 in the Graduate School and 340 in the Medical School. These students represent all 50 states and many foreign countries. For 2010, more than 18,000 applicants applied for 1,450 places in the freshman class. All undergraduates were admitted under a need-blind admission policy.

Brown’s three schools offer nearly 100 programs of study. The University adheres to a collaborative university-college model in which faculty are as committed to teaching as they are to research, embracing a curriculum that requires students to be architects of their education.

For more information, please click here

Contacts:
Martha Downs

401-863-2752

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Molecular Machines

'Spermbots' could help women trying to conceive (video) January 15th, 2016

Scientists blueprint tiny cellular 'nanomachine' December 17th, 2015

Nano-walkers take speedy leap forward with first rolling DNA-based motor: Fastest DNA motor holds potential for disease diagnostics December 1st, 2015

Rice makes light-driven nanosubmarines: Speedy single-molecule submersibles are a first November 16th, 2015

Memory Technology

A step towards keeping up with Moore's Law: POSTECH researchers develop a novel and efficient fabrication technology for cross-shaped memristor January 30th, 2016

Scientists build a neural network using plastic memristors: A group of Russian and Italian scientists have created a neural network based on polymeric memristors -- devices that can potentially be used to build fundamentally new computers January 28th, 2016

LC.300 Series Nanopositioning Controller from nPoint January 28th, 2016

First all-antiferromagnetic memory device could get digital data storage in a spin January 16th, 2016

Discoveries

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Announcements

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic