Bulk superconductivity in intercalated M$_{x}$ZrTe$_{3}$ (M=Cu, Ni)

We report the bulk superconductivity of 3d transition metal (e.g. Cu, Ni) intercalated ZrTe$_{3}$ single crystals, M$_{x}$ZrTe$_{3}$ (M=Cu, Ni). ZrTe3 shows charge density wave (CDW) transition at T$_{CDW}$=63K and the CDW nesting vector q$_{CDW}$=(1/14,0,1/3) (reciprocal space). It is metallic below 300K with an anomaly due to CDW transition and becomes filamentary superconductor below 2 K. The derived superconducting parameters indicate that M$_{x}$ZrTe$_{3}$ are bulk type-II superconductors and can be depicted in the framework of Bardeen-Cooper-Schrieffer (BCS) scenario. Intercalation depresses the CDW transition and enhances the superconductivity.