Studying Orbitals in Superconductors
Superconductivity is an interesting phenomenon of some materials that allows them to conduct electricity without resistance, but only under certain conditions. With no resistance to impair transmission, researchers have been working to understand what causes superconductivity to emerge in these materials. Researchers at Brookhaven National Laboratory have recently studied how the electron orbitals in iron-based superconductors change, as a result of dopants.
Iron-based superconductors are one kind of high temperature superconductors, which become superconducting at temperatures significantly above absolute zero, but still much lower than room temperature. They are special compounds that contain multiple elements, and the Brookhaven researchers examined how the outer-most electrons in one material are affected by the addition of a dopant, which makes the material a superconductor. The base material was barium iron arsenic, and when analyzed the electron orbitals or the iron were shown to be sandwiched between arsenic atoms. Once some cobalt atoms were doped in, the orbitals changed, creating a stronger quadrupole around the iron atoms and strongly polarizing the arsenic atoms.
This altered electronic structure helps electron couple into pairs, which is essential for superconductivity to occur. As this research was done under static conditions, and at room temperature, the researchers are going to repeat their work with super-cold samples of other materials, and perhaps help discover what creates superconductivity.
Source: Brookhaven National Laboratory