- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
|This is an orientation map of a spin-cast array of FePt nanoparticles. Most nanoparticles are enclosed by a hexagon of six neighboring nanoparticles. Each nanoparticle was color coded according to the angle (in degrees) of the hexagon's orientation.|
Researchers on North Carolina State University's Centennial Campus have investigated the viability of a technique called "spincasting" for creating thin films of nanoparticles on an underlying substrate - an important step in the creation of materials with a variety of uses, from optics to electronics.
Spincasting, which utilizes centrifugal force to distribute a liquid onto a solid substrate, already has a variety of uses. For example, it is used in the electronics industry to deposit organic thin films on silicon wafers to create transistors.
This is an orientation map of a spin-cast array of FePt nanoparticles. Most nanoparticles are enclosed by a hexagon of six neighboring nanoparticles. Each nanoparticle was color coded according to the angle (in degrees) of the hexagon's orientation.
For this study, the researchers first dispersed magnetic nanoparticles coated with ligands into a solution. The ligands, small organic molecules that bond directly to metals, facilitate the even distribution of the nanoparticles in the solution - and, later, on the substrate itself.
A drop of the solution was then placed on a silicon chip that had been coated with a layer of silicon nitride. The chip was then rotated at high speed, which spread the nanoparticle solution over the surface of the chip. As the solution dried, a thin layer of nanoparticles was left on the surface of the substrate.
Using this technique, the researchers were able to create an ordered layer of nanoparticles on the substrate, over an area covering a few square microns. "The results are promising, and this approach definitely merits further investigation," says Dr. Joe Tracy, an assistant professor of materials science and engineering at NC State and co-author of a paper describing the study.
Tracy explains that one benefit of spincasting is that it is a relatively quick way to deposit a layer of nanoparticles. "It also has commercial potential as a cost-effective way of creating nanoparticle thin films," Tracy says.
However, the approach still faces several hurdles. Tracy notes that modifications to the technique are needed, so that it can be used to coat a larger surface area with nanoparticles. Additional research is also needed to learn how, or whether, the technique can be modified to achieve a more even distribution of nanoparticles over that surface area.
Analysis of the nanoparticle films created using spincasting led to another development as well. The researchers adapted analytical tools to evaluate transmission electron microscopy images of the films they created. One benefit of using these graphical tools is their ability to identify and highlight defects in the crystalline structure of the layer. "These methods for image analysis allow us to gain a detailed understanding of how the nanoparticle size and shape distributions affect packing into monolayers," Tracy says.
The paper, "Formation and Grain Analysis of Spin Cast Magnetic Nanoparticle Monolayers," was published online March 24 by the journal Langmuir. The paper was co-authored by Tracy; NC State Ph.D. student Aaron Johnston-Peck; and former NC State post-doctoral research associate Dr. Junwei Wang. The research was funded by the National Science Foundation, the U.S. Department of Education, and Protochips, Inc.
NC State's Department of Materials Science and Engineering is part of the university's College of Engineering.
Written by Matt Shipman, NCSU News Services
About North Carolina State University
Centennial Campus (www.centennial.ncsu.edu) is an internationally recognized 1,314-acre research park and technology campus owned and operated by North Carolina University. Home to more than 60 corporate, government and non-profit partners, such as Red Hat, ABB, and the USDA, collaborative research projects vary from nanofibers and secure open systems technology to serious gaming and biomedical engineering. Four university college programs also have a significant presence on campus – College of Engineering, College of Veterinary Medicine, College of Textiles and the College of Education. NC State is one of the top research universities in the country, with expenditures in research approaching more than $325 million annually. The university ranks third among all public universities (without medical schools) in industry-sponsored research expenditures.
For more information, please click here
Dr. Joe Tracy
Copyright © North Carolina State UniversityIf you have a comment, please Contact us.
|Related News Press|
News and information
Nanospiked bacteria are the brightest hard X-ray emitters July 2nd, 2015
The quantum middle man July 2nd, 2015
Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015
Exagan Raises €5.7 Million to Produce High-efficiency GaN-on-Silicon Power-switching Devices on 200mm Wafers: Leti-and-Soitec Spinout Focused on Becoming Leading European Source Of GaN Devices for Solar, Automotive, Telecoms and Infrastructure June 25th, 2015
Nanowires could be the LEDs of the future June 25th, 2015
Leti to Present Solutions to New Applications Using 3D Technologies at SEMICON West LetiDay Event, July 14: Leti Experts also Will Speak at TechXPOT Session on MEMS and STS Session on Lithography Cost-and-Productivity Issues Below 14nm June 22nd, 2015
Producing spin-entangled electrons July 2nd, 2015
Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015
The quantum spin Hall effect is a fundamental property of light June 25th, 2015