Chameleon Magnets aka Electrically Induced Ferromagnetism at Room Temperature in Cobalt-Doped Titanium DioxidePosted: June 4th, 2011 | Author: Buster Cookson | Filed under: Applied Science, Blip, Buster Cookson, Cankler, Engineered Life, Naked Fact, Physics, Pprotoscienc, Protoscience, Quantum Physics, Technoid | Tags: Buster Cookson, Cankler, Chameleon Magnet, cobalt dioxide, Electrically Induced Ferromagnetism at Room Temperature in Cobalt-Doped Titanium Dioxide, Magnetism, nano, nano magnetism, protoscience, Quantum Physics, Spintronics, titanium dioxide, Zutic | Comments Off
Magnetism is more than just a fun property to experiment with in Science 101, not just a scientific curiosity. Scientists have discovered the Chameleon Magnet, a perminant magnet that can be switched on and off at will. Magnetism is the glue that holds every atom and molecule together.
The very small world of nano magnetism – magnatism of atom’s nd molecules - is very a different beast, not high school magnetism. In this world free electrons can be used to pass spin information on to other electrons, large groups of electrons spinning in sync can set up a magnetic field. All of these bizarre effects are being studied and applied to Chameleon Magnets and Spintronics, the science of using the spin of electrons to do work in electronics gadgets ::::
Spintronics and magnetism as it turns out are very closely related, it turns out that the spin of electrons is part of the mechanism responsible for making a material permanent magnetic. When all of the electrons in a material spin – either up or down – in the same direction a magnetic field is generated. What scientists have discovered is a mechanism that will cause the spin to synchronize using an external stimulus. In this case a voltage was applied to the material – containing cobalt and titanium dioxide - , the voltage stimulated extra free electrons – carriers – in the cobalt, these carrier electrons communicated information between the fixed cobalt electrons, causing them all to synchronize, switching on the magnetic field.
University of Buffalo researcher Igor Zutic, “Applying an electric voltage to a semiconductor injected with cobalt or other magnetic impurities may be just one way of creating a chameleon magnet. Applying heat or light to such a material could have a similar effect, freeing electrons that can then convey information about spin alignment between ions,”.
As handy as large switch on the side of a permanent magnet sounds these discoveries will be used to make our favourite gadgets better and new gadgets possible. Spintronics in general and Chameleon Magentics specifically are making new technologies possible. New better kinds of flash ram are in the works, also being investigated is the possibility of merging a computers processor and storage memory together to create instant on computing. By making a processor out of magnetic transistors it should be possible to switch the computer off without it losing it’s place or information. Switch it back on and you are straight back where you left off.
Magnetic fields are one of natures invisible forces. First discovered by French scholar Petrus Peregrinus in 1269 C.E. Magnetism is one of those forces that is well understood by science but not fully understood, leaving a number of mysteries to be solved. These latest breakthroughs are helping improve our understanding of magnetism in the small nano world.
Scientists have achieved the magnetic equivalent to a narcoleptic goat – they fall over unconscious due to stress -, an on/off switch has been added to nature. In a permanent magnetic the magnetic field is generated by all of the electrons spinning in the same direction, in sync. Electrons can spin in two directions, up or down – around their nucleus in an atom -. By adding an impurity – in this case cobalt – when making the magnet, applying voltage to the finished magnet causes free electrons to be injected – called carriers -, they communicate spin information and encourage all of the electrons to synchronize their spin, creating the magnetic field, switching it on. This isn’t the only kind of switch possible either, materials may be possible that use light or heat to flick the switch.
Spintronics is Zutic’s specialty field and it shows, his research pages are full of Spin – tronics that is -. Zutic believes these breakthroughs in spintronics will form the basis of high-capacity and low-energy memory, data storage and data transfer devices. Spintronics and the technology that comes from the research will be essential for the march of technology to continue, expect spintronics technology to take over as current technology starts to hit its limit’s.
Read more at University of Buffalo News Centre
Electrically Induced Ferromagnetism at Room Temperature in Cobalt-Doped Titanium Dioxide
- Y. Yamada1,*,
- K. Ueno2,3,*,
- T. Fukumura3,4,†,
- H. T. Yuan5,6,
- H. Shimotani5,6,
- Y. Iwasa5,6,
- L. Gu2,
- S. Tsukimoto2,
- Y. Ikuhara2,7,8, and
- M. Kawasaki1,2,5,6
1Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
2WPI-AIM Research, Tohoku University, Sendai 980-8577, Japan.
3PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan.
4Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan.
5Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
6CREST, Japan Science and Technology Agency, Tokyo 102-0075, Japan.
7Institute of Engineering Innovation, University of Tokyo, Tokyo 113-8656, Japan.
8Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, Japan.
↵* These authors contributed equally to this work.
The electric field effect in ferromagnetic semiconductors enables switching of the magnetization, which is a key technology for spintronic applications. We demonstrated electric field–induced ferromagnetism at room temperature in a magnetic oxide semiconductor, (Ti,Co)O2, by means of electric double-layer gating with high-density electron accumulation (>1014 per square centimeter). By applying a gate voltage of a few volts, a low-carrier paramagnetic state was transformed into a high-carrier ferromagnetic state, thereby revealing the considerable role of electron carriers in high-temperature ferromagnetism and demonstrating a route to room-temperature semiconductor spintronics.