Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Electronics based on a 2-D electron gas: A new material could open the door to a new kind of electronics: researchers at the Vienna University of Technology have created a stable two-dimensional electron gas in strontium titanate

This shows the atomic structure of SrTiO3(110).

Credit: TU Vienna
This shows the atomic structure of SrTiO3(110).

Credit: TU Vienna

Abstract:
Usually, microelectronic devices are made of silicon or similar semiconductors. Recently, the electronic properties of metal oxides have become quite interesting. These materials are more complex, yet offer a broader range of possibilities to tune their properties. An important breakthrough has now been achieved at the Vienna University of Technology: a two dimensional electron gas was created in strontium titanate. In a thin layer just below the surface electrons can move freely and occupy different quantum states.

Electronics based on a 2-D electron gas: A new material could open the door to a new kind of electronics: researchers at the Vienna University of Technology have created a stable two-dimensional electron gas in strontium titanate

Vienna, Austria | Posted on March 3rd, 2014

Strontium titanate is not only a potential future alternative to standard semiconductors, it could also exhibit interesting phenomena, such as superconductivity, thermoelectricity or magnetic effects that do not occur in the materials that are used for today's electronic devices.

The Surface Layer and the Inside

This project closely links theoretical calculations and experiments. Zhiming Wang from Professor Ulrike Diebold's research team was the leading experimentalist; some of the experimental work was done at the synchrotron BESSY in Berlin. Zhicheng Zhong from Professor Karsten Held's group studied the material in computer simulations.

Not all of the atoms of strontium titanate are arranged in the same pattern: if the material is cut at a certain angle, the atoms of the surface layer form a structure, which is different from the structure in the bulk of the material. "Inside, every titanium atom has six neighbouring oxygen atoms, whereas the titanium atoms at the surface are only connected to four oxygen atoms each", says Ulrike Diebold. This is the reason for the remarkable chemical stability of the surface. Normally such materials are damaged if they come into contact with water or oxygen.

Migrating Oxygen Atoms

Something remarkable happens when the material is irradiated with high-energy electromagnetic waves: "The radiation can remove oxygen atoms from the surface", Ulrike Diebold explains. Then other oxygen atoms from within the bulk of the material move up to the surface. Inside the material, an oxygen deficiency builds up, as well a surplus of electrons.

"These electrons, located in a two dimensional layer very close to the surface, can move freely. We call this an electron gas", says Karsten Held. There has already been some evidence of two dimensional electron gases in similar materials, but until now the creation of a stable, durable electron gas at a surface has been impossible. The properties of the electrons in the gas can be finely tuned. Depending on the intensity of the radiation, the number of electrons varies. By adding different atoms, the electronic properties can also be changed.

"In solid state physics, the so-called band structure of a material is very important. It describes the relationship between the energy and the momentum of the electrons. The remarkable thing about our surface is that it shows completely different kinds of band structures, depending on the quantum state of the electron", says Karsten Held.

The electron gas in the new material exhibits a multitude of different electronic structures. Some of them could very well be suitable for producing interesting magnetic effects or superconductivity. The promising properties of strontium titanate will now be further investigated. The researchers hope that, by applying external electric fields or by placing additional metal atoms on the surface, the new material could reveal a few more of its secrets.

####

For more information, please click here

Contacts:
Prof. Ulrike Diebold
Institute for Applied Physics
Vienna University of Technology
Wiedner Hauptstraße 8-10, 1040 Wien
+43-1- 58801-13425


Prof. Karsten Held
Institut for Solid State Physics
Vienna University of Technology
Wiedner Hauptstraße 8
T: +43-1-58801-13710


Florian Aigner

43-158-801-41027
Vienna University of Technology

Copyright © Vienna University of Technology

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

News and information

The next step in DNA computing: GPS mapping? May 6th, 2015

Improving Clinical Care and Patient Quality of Life in Advanced Liver Disease, d-LIVER Workshop, Milan, 27 May 2015 May 6th, 2015

Grafoid Acquires MuAnalysis Inc; Expands Its Advanced Materials Testing Capabilities May 6th, 2015

Winner Announced for NNI’s First ‘EnvisioNano’ Nanotechnology Image Contest May 6th, 2015

Superconductivity

Oxford Instruments announces winners of the 2015 Sir Martin Wood Science Prize for China May 2nd, 2015

Novel superconducting undulator provides first x-ray light at ANKA May 1st, 2015

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

Chip Technology

The next step in DNA computing: GPS mapping? May 6th, 2015

Improving organic transistors that drive flexible and conformable electronics: UMass Amherst scientists advance understanding of strain effects on performance May 5th, 2015

New chip architecture may provide foundation for quantum computer: Researchers at the Georgia Tech Research Institute have developed a microfabricated ion trap architecture that holds promise for increasing the density of qubits in future quantum computers May 5th, 2015

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

Discoveries

Thermometer-like device could help diagnose heart attacks May 6th, 2015

The next step in DNA computing: GPS mapping? May 6th, 2015

Field-effect transistors on hybrid perovskites fabricated for first time May 6th, 2015

Improving organic transistors that drive flexible and conformable electronics: UMass Amherst scientists advance understanding of strain effects on performance May 5th, 2015

Announcements

The next step in DNA computing: GPS mapping? May 6th, 2015

Improving Clinical Care and Patient Quality of Life in Advanced Liver Disease, d-LIVER Workshop, Milan, 27 May 2015 May 6th, 2015

Grafoid Acquires MuAnalysis Inc; Expands Its Advanced Materials Testing Capabilities May 6th, 2015

Winner Announced for NNI’s First ‘EnvisioNano’ Nanotechnology Image Contest May 6th, 2015

Quantum nanoscience

Quantum particles at play: Game theory elucidates the collective behavior of bosons April 29th, 2015

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

More is less in novel electronic material: Adding electrons actually shrinks the system April 27th, 2015

Quantum 'paparazzi' film photons in the act of pairing up April 22nd, 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