2009/11/30 by J. E. Sonier, C. V. Kaiser, V. Pacradouni +5
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Copper oxide #Doping #Ferromagnetism #Magnetic and transport properties of perovskites and related materials #Magnetic moment #Magnetism #Materials science #Muon spin spectroscopy #Oxide #Phase (matter) #Physics #Physics of Superconductivity and Magnetism #Superconductivity #cond-mat.supr-con
paper · pdf · doi:10.1073/pnas.1007079107
published as Proc. Natl. Acad. Sci. USA 107, 17131-17134 (2010) · 13 pages, 5 figures
openalex publication_date 2010/09/20 · arxiv created 2010/12/01 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The doping of charge carriers into the CuO(2) planes of copper oxide Mott insulators causes a gradual destruction of antiferromagnetism and the emergence of high-temperature superconductivity. Optimal superconductivity is achieved at a doping concentration p beyond which further increases in doping cause a weakening and eventual disappearance of superconductivity. A potential explanation for this demise is that ferromagnetic fluctuations compete with superconductivity in the overdoped regime. In this case, a ferromagnetic phase at very low temperatures is predicted to exist beyond the doping concentration at which superconductivity disappears. Here we report on a direct examination of this scenario in overdoped La(2-x)Sr(x)CuO(4) using the technique of muon spin relaxation. We detect the onset of static magnetic moments of electronic origin at low temperature in the heavily overdoped nonsuperconducting region. However, the magnetism does not exist in a commensurate long-range ordered state. Instead it appears as a dilute concentration of static magnetic moments. This finding places severe restrictions on the form of ferromagnetism that may exist in the overdoped regime. Although an extrinsic impurity cannot be absolutely ruled out as the source of the magnetism that does occur, the results presented here lend support to electronic band calculations that predict the occurrence of weak localized ferromagnetism at high doping.