Landmark discovery has magnetic appeal for scientists
A fundamental problem that has puzzled generations of scientists has finally been solved after more than 70 years. An international team of scientists has discovered a subtle electronic effect in magnetite – the most magnetic of all naturally occurring minerals – causes a dramatic change to how this material conducts electricity at very low temperatures.
The discovery gives new insight into the mineral in which mankind discovered magnetism, and it may enable magnetite and similar materials to be exploited in new ways.
The research, published in Nature, was led by the University of Edinburgh in collaboration with the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, where the experiments were conducted.
The magnetic properties of magnetite have been known for more than 2000 years and gave rise to the original concepts of magnets and magnetism. The mineral has also formed the basis for decades of research into magnetic recording and information storage materials.
In 1939, Dutch scientist Evert Verwey discovered that the electrical conductivity of magnetite decreases abruptly and dramatically at low temperatures. At about 125 Kelvin, or minus 150 degrees Celsius, the metallic mineral turns into an insulator. Despite many efforts, until now the reason for this transition has been debated and remained controversial.
When the team of scientists fired an intense X-ray beam at a tiny crystal of magnetite at very low temperatures, they were able to understand the subtle rearrangement of the mineral's chemical structure. Electrons are being trapped within groups of three iron atoms where they can no longer transport an electrical current.
Dr Jon Wright of the ESRF said: "Our main challenge was to obtain a perfect crystal, which meant using one that was tiny, just half the diameter of a human hair. Then we needed to observe subtle changes in this microscopic sample as we lowered the temperature. In Europe, this is only possible at the ESRF, thanks to the extremely high energy of its synchrotron X-rays."
Professor Paul Attfield, of the University of Edinburgh, said: "We have solved a fundamental problem in understanding the original magnetic material, upon which everything we know about magnetism is built. This vital insight into how magnetite is constructed and how it behaves will help in the development of future electronic and magnetic technologies."
Provided by University of Edinburgh
-
From lemons to lemonade: Reaction uses carbon dioxide to make carbon-based semiconductor,
32 comments
-
Thioridazine kills cancer stem cells in human while avoiding toxic side-effects of conventional cancer treatments,
3 comments
-
SpaceX private rocket blasts off for space station (Update),
42 comments
-
Climate scientists say they have solved riddle of rising sea,
31 comments
-
SpaceX capsule has 'new car' smell, astronauts say (Update),
4 comments
-
Why does a boiled egg rotates while a raw egg doesn't?
23 minutes ago
-
Lightning strike in mindair
31 minutes ago
-
Why does light move?
2 hours ago
-
How to calculate the repulsion force between a permanent and an electromagnet?
3 hours ago
-
Why does light allow us to see things?
3 hours ago
-
Room temperature superconductivity
3 hours ago
- More from Physics Forums - General Physics
More news stories
Is a classical electrodynamics law incompatible with special relativity?
(Phys.org) -- The laws of classical electromagnetism that were developed in the 19th century are the same laws that scientists use today. They include Maxwell’s four equations along with the Lorentz la ...
May 24, 2012 |
4.7 / 5 (18) |
43
|
Landmark calculation clears the way to answering how matter is formed
(Phys.org) -- An international collaboration of scientists, including Thomas Blum, associate professor of physics, is reporting in landmark detail the decay process of a subatomic particle called a kaon – ...
May 25, 2012 |
4.3 / 5 (22) |
51
|
Lying in wait for WIMPs: Researchers seek to dramatically increase sensitivity of Large Underground Xenon detector
Although it's invisible, dark matter accounts for at least 80 percent of the matter in the universe. No one knows what it is, but most scientists would bet on weakly interacting massive particles, or WIMPs.
May 23, 2012 |
4 / 5 (7) |
16
|
Hawaii lab turns laser-powered bubbles into microrobots
(Phys.org) -- A team of scientists from the University of Hawaii are working on microrobots created from bubbles of air in a saline solution. The bubbles take on their title of “robots” as a laser ...
May 23, 2012 |
5 / 5 (4) |
2
|
Sound increases the efficiency of boiling
Scientists at the Georgia Institute of Technology achieved a 17-percent increase in boiling efficiency by using an acoustic field to enhance heat transfer. The acoustic field does this by efficiently removing vapor bubbles ...
May 24, 2012 |
5 / 5 (2) |
2
Nvidia trumpets Tegra 3 phone design wins for 2012
(Phys.org) -- Nvidia’s competitive war paint has a name, Tegra 3. On the heels of Nvidia announcements about lowering costs of its Tegra 3 processors and Nvidia-enabled tablets running Android Ice Cream ...
'Unzipped' carbon nanotubes could help energize fuel cells, batteries
Multi-walled carbon nanotubes riddled with defects and impurities on the outside could replace some of the expensive platinum catalysts used in fuel cells and metal-air batteries, according to scientists at ...
T cells 'hunt' parasites like animal predators seek prey, study shows
By pairing an intimate knowledge of immune-system function with a deep understanding of statistical physics, a cross-disciplinary team at the University of Pennsylvania has arrived at a surprising finding: T cells use a movement ...
Computer model used to pinpoint prime materials for efficient carbon capture
When power plants begin capturing their carbon emissions to reduce greenhouse gases – and to most in the electric power industry, it's a question of when, not if – it will be an expensive undertaking.
Change in developmental timing was crucial in the evolutionary shift from dinosaurs to birds: study
At first glance, it's hard to see how a common house sparrow and a Tyrannosaurus Rex might have anything in common. After all, one is a bird that weighs less than an ounce, and the other is a dinosaur that ...
Land and sea species differ in climate change response: study
(Phys.org) -- Marine and terrestrial species will likely differ in their responses to climate warming, new research by Simon Fraser University and Australia’s University of Tasmania has found.
Dec 21, 2011
Rank: 3 / 5 (1)
BOOO on the author -- why is this important - how can it be exploited -- anything ??? anyone out there
Dec 21, 2011
Rank: 1 / 5 (4)
Dec 21, 2011
Rank: 1 / 5 (2)
Dec 21, 2011
Rank: 1 / 5 (2)
http://en.wikiped...nsulator
The other thing is exact modeling of it with hard numbers. But the fact, we cannot compute the boiling point of water doesn't mean, we don't understand what happens there. Actually, such modeling will not enable us to understand the boiling of fluids a much better, then we already do. But it can still serve as a good salary generator for physicists involved - and this is actually what it's important in contemporary science. It has no meaning to cover it.
http://www.aether...memo.gif
Dec 21, 2011
Rank: not rated yet
Actually, magnetism can be derived from relativity. It is a relativistic effect due to length contraction and time dilation that charges appear to undergo when they are moving relative to something else.
Here is a good explanation:
http://skepticspl...ism.html
So, no, we do understand where magnetism comes from as long as we accept the postulates of relativity as fundamental to reality.