Featured Research

from universities, journals, and other organizations

New technique controls crystalline structure of titanium dioxide

Date:
June 27, 2012
Source:
North Carolina State University
Summary:
Researchers have developed a new technique for controlling the crystalline structure of titanium dioxide at room temperature. The development should make titanium dioxide more efficient in a range of applications, including photovoltaic cells, hydrogen production, antimicrobial coatings, smart sensors and optical communication technologies.

The new technique allows researchers to control the phase of the titanium dioxide by modifying the structure of the titanium trioxide and sapphire substrate.

Researchers from North Carolina State University have developed a new technique for controlling the crystalline structure of titanium dioxide at room temperature. The development should make titanium dioxide more efficient in a range of applications, including photovoltaic cells, hydrogen production, antimicrobial coatings, smart sensors and optical communication technologies.

Titanium dioxide most commonly comes in one on of two major "phases," meaning that its atoms arrange themselves in one of two crystalline structures. These phases are "anatase" or "rutile." The arrangement of atoms dictates the material's optical, chemical and electronic properties. As a result, each phase has different characteristics. The anatase phase has characteristics that make it better suited for use as an antibacterial agent and for applications such as hydrogen production. The rutile phase is better suited for use in other applications, such as photovoltaic cells, smart sensors and optical communication technologies.

"Traditionally, it has been a challenge to stabilize titanium dioxide in the desired phase," says Dr. Jay Narayan, John C. Fan Distinguished Chair Professor of Materials Science and Engineering at NC State and co-author of a paper describing the work. "The material tends to transform into the anatase phase below 500 degrees Celsius [C], and transform into the rutile phase at temperatures above 500 C.

"We have now developed a technique that precisely controls the phase, or crystalline structure, of titanium dioxide at room temperature -- and stabilizes that phase, so it won't change when the temperature fluctuates. This process, called phase tuning, allows us to fine-tune the structure of the titanium dioxide, so that it has the optimal structure for a desired application."

The process begins by using a widely available sapphire substrate that has the desired crystalline structure. Researchers then grow a template layer of titanium trioxide on the substrate. The structure of the titanium trioxide mimics the structure of the sapphire substrate. The titanium dioxide is then grown on top of the titanium trioxide template layer.

The structure of the titanium dioxide differs from the titanium trioxide -- but is dictated by the structure of that template layer. This means that you can create the titanium dioxide in any phase, simply by modifying the structure of the titanium trioxide and sapphire substrate.

This works because of a process called domain matching epitaxy (DME). In DME, the lattice planes in the template layer line up with the lattice planes of the material being grown on that template. Lattice planes are the lines, or walls, which constitute a crystal.

The researchers have also demonstrated how this technique can be used with silicon computer chip substrates, which can be integrated into electronics such as smart sensors.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. R. Bayati, R. Molaei, R. J. Narayan, J. Narayan, H. Zhou, S. J. Pennycook. Domain epitaxy in TiO2/α-Al2O3 thin film heterostructures with Ti2O3 transient layer. Applied Physics Letters, 2012; 100 (25): 251606 DOI: 10.1063/1.4729937

Cite This Page:

North Carolina State University. "New technique controls crystalline structure of titanium dioxide." ScienceDaily. ScienceDaily, 27 June 2012. <www.sciencedaily.com/releases/2012/06/120627103310.htm>.
North Carolina State University. (2012, June 27). New technique controls crystalline structure of titanium dioxide. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2012/06/120627103310.htm
North Carolina State University. "New technique controls crystalline structure of titanium dioxide." ScienceDaily. www.sciencedaily.com/releases/2012/06/120627103310.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins