Nanotechnology Now





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

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

UCLA nanoscientists are first to model atomic structures of three bacterial nanomachines: Cryo electron microscope enables scientists to explore the frontiers of targeted antibiotics April 21st, 2015

Advances in molecular electronics: Lights on -- molecule on: Researchers from Dresden and Konstanz succeed in light-controlled molecule switching April 20th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Memory Technology

Advance in quantum error correction: Protocol corrects virtually all errors in quantum memory, but requires little measure of quantum states May 27th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Nano memory cell can mimic the brain’s long-term memory May 14th, 2015

Silicon Storage Technology and GLOBALFOUNDRIES Announce Qualification of Automotive Grade 55nm Embedded Flash Memory Technology May 5th, 2015

Discoveries

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Announcements

TCL Unveils First 65” TV Featuring QD Vision’s Color IQ™ Quantum Dot Technology: Emerging industry leader introduces expanded quantum dot TV lineup May 30th, 2015

Nanotech Secures Additional Patents in Advanced Security Features: New patented features gain attention from the banknote industry May 30th, 2015

New 'designer carbon' from Stanford boosts battery performance May 30th, 2015

Two UCSB Professors Receive Early Career Research Awards: The Department of Energy’s award for young scientists acknowledges UC Santa Barbara’s standing as a top tier research institution May 29th, 2015

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