The researchers first created separate nanoparticles of two materials, lead selenide and magnetic iron oxide, with precise dimensions.
Even so, he pointed out that some nanoparticles potentially serving as the basis for savvy devices of the future are already in use, including magnetic iron oxide particles used for advanced body imaging.
That would change the way the magnetic field of the iron oxide interacts with the semiconducting behaviour of the lead selenide.
In some of the packing arrangements, the quantum dots are huddled together, and thus are less susceptible to the magnetic field from the iron oxide nanoparticles.
We're not going to front like we understand exactly how it works, but two IBM researchers in California have announced that they've gotten closer to controlling the orientation and magnetic spin of individual iron atoms on a copper surface, which would have huge implications for nanotech storage -- imagine the basic tech in your hard drive shrunk down the molecular level.
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But as a back-up the Rochester researchers are also considering a magnetic technique that would be able to detect iron particles left over from the original ink, even in places where the pigment itself has faded away completely.
The result was that the nail could attract little bits of iron on a table thanks to the magnetic field.
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Iron oxide is used in coatings for magnetic recording materials.
Dr Ropars suspects it was being used as a sunstone because the magnetic compasses of the day were thrown out of kilter by iron cannon.
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Of course, they didn't just use any old off the shelf magnet, instead designing custom neodymium iron-boron models that produce just the right magnetic field necessary to make that hard drive completely useless.
The inner core, made of very pure, solid iron, rotates along with the outer core, dragging the Earth's magnetic field with them.
On it's own, oil is not magnetic, but MIT researchers say that when mixed with water-repellent nanoparticles that contain iron, the oil can be magnetically separated from the water.
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