Uranium rhodium germanium (URhGe) is the first discovered
metal
A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...
that becomes
superconducting in the presence of an extremely strong
electromagnetic field
An electromagnetic field (also EM field or EMF) is a classical (i.e. non-quantum) field produced by (stationary or moving) electric charges. It is the field described by classical electrodynamics (a classical field theory) and is the classical ...
. Very unlike other superconducting materials, whose superconducting properties can be lost due to strong magnetic fields, uranium rhodium germanium actually regains superconducting abilities at about 8
teslas.
Process
URhGe's
critical temperature
Critical or Critically may refer to:
*Critical, or critical but stable, medical states
**Critical, or intensive care medicine
* Critical juncture, a discontinuous change studied in the social sciences.
* Critical Software, a company specializing ...
(''T
c'') is normally about 280
millikelvins.
The Grenoble team in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
, headed by
Andrew D. Huxley, first cooled down the sample below its critical temperature and raised the magnetic field to 2 T. As expected, the sample's superconducting properties vanished. However, when the team raised the magnetic field to 8 T, the superconducting behavior continued. The critical temperature at that field strength increased to about 400 millikelvins. The sample retained the superconducting state until 13 T. They also found that at 12 T, the URhGe sample experienced a magnetic
phase transition
In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states ...
.
References
*{{cite journal, doi=10.1126/science.1115498, title=Magnetic Field-Induced Superconductivity in the Ferromagnet URhGe, year=2005, last1=Levy, first1=F., journal=Science, volume=309, issue=5739, pages=1343–6, pmid=16123293, last2=Sheikin, first2=I, last3=Grenier, first3=B, last4=Huxley, first4=AD, bibcode=2005Sci...309.1343L, s2cid=38460998
Intermetallics
Superconductors
Correlated electrons
Alloys
Uranium compounds
Germanium compounds
Rhodium compounds