Magnets have many uses in industrial and power applications. For instance semiconductors are designed to have magnetic energy that can convey small and large quantities of information, so they are at the core of modern day computers and cell phones. Not satisfied with the current ability and magnet energy of semi conductors scientist are trying to get them to do a lot more than just convey data, particularly to perform functions like electronic control and data recording.  Read more about Nanotechnology in the Energy Industry: Applications and Market Potential

In the past they were only marginally successful in achieving these results because of strict temperature requirements required in harnessing magnet energy; most of the effects were only apparent at extremely cold temperatures in the range of minus 260 degrees Celsius. Such extreme temperature requirements made their use in computers impossible.

However a research conducted at the University of Washington has given a new ray of hope to scientist working on magnet energy the world over. The results of the experiment were reported in ‘Science’ on Aug 21. The report confirms that researchers have finally managed to get their hands on a technology that will help them to get the best of magnetic energy in the form of tiny semiconductor crystals known as quantum dots or nanocrystals. These small semiconductor crystals display magnetic functions at room temperature when light is used as a trigger.

Generally the magnetic energy of silicon semiconductors is harnessed by incorporating tiny transistors in them. These transistors are responsible for manipulating the electrons based on their charge. Scientists are also exploring other triggers that may allow them to achieve the magnetic energy that they want, for instance the use of electricity to manipulate electrons is known as ‘spin’. However, the research is still in its infancy and the search is still on for spintronics that will function at room temperature without losing the magnetic energy that they display at sub zero levels.

The research team with Daniel Gamelin, with a UW chemistry professor at the helm, has found an innovative way to use photons to access magnetic energy at room temperatures. Photons are tiny light particles that can be used to manipulate the magnetic properties of a semiconductor nanaocrystals thus letting scientist access magnetic energy even at room temperature.

The research has provided new insight into the field of microelectronics because if spin can be used instead of a charge as the trigger and if photons can be used to manipulate the process, this would equate to the possibility of materials that will not only store information but also perform logic functions without the need for sub zero temperatures.

The ideal composition to generate this effect of magnetic energy was found in a combination of cadmium-selenium semiconductors knows as cadmium selenide. However, some ions of the compound were replaced with magnetic manganese ions. The resultant crystals which are only ten nanometers in size were suspended in a colloid solution. Then beams of photons were passed through the solution. This resulted in the aligning of all manganese ions creating a magnetic field 500 times stronger than the one created by crystals that lacked the manganese ions. Even though the magnetic energy was more pronounced at lower temperatures it remained conspicuously high even at room temperature.

Another paper authored by Gamelin and his group which appeared on Sunday Aug 16 in Nature Nanotechnology stated that similar magnetic energy effects were noted in zinc oxide semiconductors with an inclusion of manganese ions. However, in case of zinc oxide semiconductors the photons imitated the effect of an on off switch so the changes brought about by the application of the photon beam stayed in place till another stimulus was applied.

For the purpose of this paper, Stefan Ochsenbein, Yong Feng, Kelly Whitaker, Ekaterina Badaeva, William Liu and Xiaosong Li, all of the UW also collaborated on the project with Gamelin.

Even though some of these magnetic energy behaviors were observed in earlier studies conducted at low temperatures but since the active crystals were embedded in other active material the effects of magnetic energy could not be conclusively isolated. The suspension in colloid solution rendered a new functional form to the magnetic energy which could make integration with unconventional material possible. For instance, the solution containing the crystals could be applied to a film using a device resembling an inkjet printer or used with techniques not practical for typical magnetic semiconductors.

Gamelin further added that through the research they had managed to get the spin effect into a processable form leading to the birth of exciting new technologies. The research was funded by the Dreyfus Foundation, U.S. National Science Foundation, University of Washington, the Sloan Foundation, the German Research Foundation, Gaussian Inc, the Natural Sciences and Engineering Research Council of Canada, the Research Corp and the Swiss National Science Foundation