The itinerant state of carriers in pnictide NaCu2P2: Role of distortion in CuP4 tetrahedra
Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences - P.O. Box 603, Beijing 100190, China
Accepted: 10 November 2010
A new copper-based pnictide NaCu2P2, which is isostructural to the superconductor LiCu2P2, has been synthesized. The structural analysis reveals that the CuP4 tetrahedra of this compound are much flattened exhibiting a bigger P-Cu-P angle and a shorter thickness of the P-Cu2-P layer compared with its counterparts in LiCu2P2. It shows metal-like conducting behavior over a temperature range from room temperature down to 2 K. Magnetic measurement indicates it is diamagnetic over the same temperature range. The structural distortion in CuP4 tetrahedra is thought to be responsible for the metallic character and the absence of superconductivity above 1.65 K. The results demonstrate the distortion in the tetrahedra plays an important role in determining the carrier state in pnictides.
PACS: 74.70.Dd – Ternary, quaternary, and multinary compounds (including Chevrel phases, borocarbides, etc.) / 74.62.Dh – Effects of crystal defects, doping and substitution / 74.62.Bf – Effects of material synthesis, crystal structure, and chemical composition
© EPLA, 2010