Abstract

2H-Ni_0.02TaSe₂ single crystals were successfully grown via the iodine vapor transport technique. The typical dimension of the crystal is about 3×2×0.5 mm³. Compared with the parent compound 2H-TaSe₂ with a superconducting transition temperature T_C=0.14 K, the electronic transport, specific-heat and magnetization results indicate that the superconductivity of the Ni_0.02TaSe₂ single crystal is obviously enhanced (T_C=2.79 K). In addition, it is found that the incommensurate charge-density-wave (ICDW) disappears while the commensurate charge-density-wave (CCDW) shifts to about 96.2 K with the intercalation of a little of Ni. It clearly indicates that there is a competition between superconductivity (SC) and charge-density-wave (CDW) order for 2H-TaSe₂ system and that between SC and ICDW is more drastic.