Scientists at the University of Minnesota have managed for the first time in the history of science to “turn on” magnetism in a material that is nonmagnetic under normal conditions using electricity. This achievement could be a step toward creating electronic components from fairly common materials that could not be used for this purpose in their normal form.
Let us remind our readers that ferromagnetism is one of the strongest properties of some materials in which the electrons of its atoms rotate synchronously in one direction; in non-magnetic materials, the electrons are divided into conditional pairs moving in opposite directions, which suppresses the magnetic field they generate. There are not many naturally occurring ferromagnetic materials, the most common being iron, cobalt, and nickel, as well as their alloys. And this significantly narrows the possibilities of engineers who create electronic devices that work by using the phenomenon of ferromagnetism.
The material in question is called pyrite, an iron disulfide that looks a lot like gold. This material is under normal conditions a completely nonmagnetic material, but when scientists brought a pyrite crystal into contact with an electrolyte of a certain ionic composition, and applied a small electrical potential of about one volt to all this, a very strange effect occurred. The electric potential caused the positively charged parts of the molecules to move toward the contact point between the pyrite and the electrolyte, creating a magnetic field whose strength could be measured with ordinary instruments. And the most interesting thing was that after the potential was removed, the pyrite had magnetic properties that would make it possible to use this magnetic form of the material in electronics.
“We ourselves were surprised by the effect obtained,” the researchers write, “By applying voltage, we essentially ‘pour’ electrons inside the material. And when a high enough concentration of electrons appears inside the material, the material spontaneously becomes a ferromagnet. After we pulled this trick with iron sulfide, we’re pretty sure it could work with other common materials, too.”
Note that scientists have previously managed to turn nonmagnetic materials into magnetic ones by removing electrons rotating in the same direction from them. And this case is the first in the history of science, when the same effect was obtained only with electricity and by filling the material with additional electrons. Next, the researchers plan to continue working in this direction and make the effect work at higher temperatures and with other types of initially nonmagnetic materials.