Uranium rhodium germanium (URhGe) is the first discovered

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

that becomes

superconducting Superconductivity is a set of physical properties observed in certain materials where Electrical resistance and conductance, electrical resistance vanishes and magnetic field, magnetic flux fields are expelled from the material. Any material e ...

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 c ...

. 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 in ...

(''T_c'') is normally about 280

millikelvin List of orders of magnitude for temperature Detailed list for 100 K to 1000 K Most ordinary human activity takes place at temperatures of this order of magnitude. Circumstances where water naturally occurs in liquid form are shown in light gr ...

s. The Grenoble team in

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, 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 of ...

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