Superconductivity from magnetic elements under high pressure

• Published in: Physica. B, Condensed matter Condensed matter, 2006-05, Vol.378, p.632-635
• Main Authors: Shimizu, Katsuya, Amaya, Kiichi, Suzuki, Naoshi, Ōnuki, Yoshichika
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.); High pressure; Iron; Magnetic properties; Magnetism; Oxygen; Physics; Properties of type I and type II superconductors; Superconductivity
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2006.01.182

Can we expect the appearance of superconductivity from magnetic elements? In general, superconductivity occurs in nonmagnetic metal at low temperature and magnetic impurities destroy superconductivity; magnetism and superconductivity are as incompatible as oil and water. Here, we present our experimental example of superconducting elements, iron and oxygen. They are magnetic at ambient pressure, however, they become nonmagnetic under high pressure, then superconductor at low temperature. What is the driving force of the superconductivity? Our understanding in the early stages was a simple scenario that the superconductive state was obtained as a consequence of an emergence of the nonmagnetic states. In both cases, we may consider another scenario for the appearance of superconductivity; the magnetic fluctuation mechanism in the same way as unconventional superconductors.