Synthesis, Crystal Structure, and Electrical Conductivity of Pd-intercalated NbSe2

New intercalated compounds Pd x NbSe 2 (x=0-0.17) were synthesized via solid-state reaction. They possess the parent structure of 2H-NbSe 2 and crystalize in the hexagonal space group of P6 3 /mmc. The intercalated Pd occupies the octahedral position in the van der Waals gaps of 2H-NbSe 2 . Unit cell parameter c increases linearly with the Pd content, while a is nearly unchanged. The lattice parameter of Pd 0.17 NbSe 2 (a=b=0.34611(2) nm, c= 1.27004(11) nm) is identified by single crystal X-ray diffraction. The intercalated Pd stabilizes the crystal structure of NbSe 2 by connecting the adjacent Nb-Se layers with [PdSe 6 ] octahedra and leads to the enhanced thermostability in air. Temperature dependence of electric resistivity reveals that the residual resistivity ratio of Pd x NbSe 2 monotonically decreases with addition of the intercalated Pd content. The decreased superconducting critical temperature of Pd x NbSe 2 indicates the suppression effect of Pd intercalation on the superconductivity in the host NbSe 2 .