Weird Reason Plutonium Doesn't Act Like Other Metals
Plutonium is a metal, but it won't stick to a magnet, puzzling scientists for decades. Now researchers may have found this "missing magnetism."
The hideout? Electrons that surround every atom of plutonium, finds the group, led by Marc Janoschek of Los Alamos National Laboratory.
The finding, they say, could lead to the ability to predict and tune the properties of new materials more precisely.
To figure out what plutonium's electrons looked like in this ground state, Janoschek's team fired a beam of neutrons at a plutonium sample. The neutrons and electrons both have magnetic fields, and those fields have magnetic moments. A magnetic moment refers to the amount and direction of the force needed to align an object in a magnetic field. As the neutrons' and electrons' moments interacted, Janoschek's team observed a kind of signature of the electrons' ground states, which revealed the number of electrons in the outer shell.
That's when they found plutonium could have four, five or six electrons in the outer shell in the ground state. Scientists who were trying to explain the element's odd properties previously had assumed the number was fixed.
But that's not what the new study showed. "It fluctuates between the three different configurations," Janoschek said. "It is in all three at the same time."
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