A New Quasi-One-Dimensional Ternary Molybdenum Pnictide Rb<sub>2</sub>Mo<sub>3</sub>As<sub>3</sub> with Superconducting Transition at 10.5K
Kang Zhao, Qing-Ge Mu, Bin-Bin Ruan, Menghu Zhou, Qingsong Yang, Tong Liu, Bo-Jin Pan, Shuai Zhang, Genfu Chen, Zhi-An Ren
Abstract
We report superconductivity in a new ternary molybdenum pnictide Rb 2 Mo 3 As 3 , synthesized via the solid state reaction method. Powder x-ray diffraction analysis reveals a hexagonal crystal structure with space group <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>P</mml:mi> <mml:mover accent="true"> <mml:mn>6</mml:mn> <mml:mo stretchy="false">¯</mml:mo> </mml:mover> <mml:mi>m</mml:mi> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> (No. 187), and the refined lattice parameters are a = 10.431(5) Å, c = 4.460(4) Å. SEM images show rod-like grains with good ductility, confirming a quasi-one-dimensional (Q1D) structure. Electrical resistivity and dc magnetic susceptibility characterizations exhibit superconductivity with an onset of T c = 10.5 K. The upper critical field of Rb 2 Mo 3 As 3 is estimated to be 28.2T at zero temperature, providing an evidence of possible unconventional superconductivity. Our recent discovery of MoAs-based superconductors above 10 K provides a unique platform for the study of exotic superconductivity in 4 d electron systems with Q1D crystal structures.