The British research team proved that "molecular enthalpy" makes non-magnetic metals magnetic
Of the various materials, iron is the most widely known ferromagnetic material. A material science paper published this week in the British journal Nature describes a technique that allows non-magnetic metals such as manganese and copper to be magnetic at room temperature. This study, because of "molecular enthalpy", allows metals to overcome the "Stoner criterion" and helps broaden the range of materials and materials used in magnetic and spintronic devices.
Physical ferromagnetism refers to the magnetic state of a material with a spontaneous magnetization phenomenon. That is to say, some materials are magnetized by the action of an external magnetic field, and even if the external magnetic field disappears, the magnetization state can be maintained and magnetic. Inside the ferromagnetic material, there are many unpaired electrons. But pure ferromagnetism is very rare, because the magnetic phenomenon of matter has a critical temperature, which occurs at this temperature, and only three elements can be magnetic at room temperature: iron, cobalt and nickel. Because the magnetic properties of metals are not only due to the presence of unpaired electrons, but also the interaction between these electrons.
The University of Leeds, Oscar Sespides and his research team, demonstrated that copper and manganese films can be magnetized by capturing electrons between the metal and an organic molecule. This organic molecule is a spherical fullerene with 60 carbon atoms. The reason why fullerenes are selected as model molecules is that their structure is simple and stable. Such "molecular defects" allow metals to overcome the "Stoner criterion." This theory holds that in ferromagnetic metals, there is a positive exchange between electrons, which corresponds to the presence of an internal magnetic field in the positive direction. The "Stoner criterion" is a theory that explains why iron is magnetic and manganese does not, although the two elements have similar electronic properties and are adjacent in the periodic table.
In the relevant news and opinion articles of this paper, Kasik Raman and Jagadesh Modra of the Tata Institute of Basic Research in India said that the research results may be for the development of a new generation of unconventional magnetic hybrids. Nanoelectronic devices made of materials paved the way.
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