Nickel-Based Oxyphosphide Superconductor with a Layered Crystal Structure, LaNiOP

• Published in: Inorganic chemistry Vol. 46; no. 19; pp. 7719 - 7721
• Main Authors: Watanabe, Takumi, Yanagi, Hiroshi, Kamiya, Toshio, Kamihara, Yoichi, Hiramatsu, Hidenori, Hirano, Masahiro, Hosono, Hideo
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17.09.2007
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic701200e

A layered oxyphosphide, LaNiOP, was synthesized by solid-state reactions. This crystal was confirmed to have a layered structure composed of an alternating stack of (La3+O2-)+ and (Ni2+P3-)-. We found that the resulting LaNiOP shows a superconducting transition at ∼3 K. This material exhibited metallic conduction and Pauli paramagnetism in the temperature range of 4−300 K. The resistivity sharply dropped to zero and the magnetic susceptibility became negative at <4 K, indicating that a superconducting transition occurs. The volume fraction of the superconducting phase estimated from the diamagnetic susceptibility reached ∼40 vol % at 1.8 K, substantiating that LaNiOP is a bulk superconductor.