Menghu Zhou

We report the crystal and electronic structures, charge density wave (CDW), and superconductivity of polycrystalline 4Ha−NbSe2 studied by x-ray diffraction, ab initio calculations, electrical resistivity, magnetization, and specific heat. 4Ha−NbSe2 has no central inversion symmetry (space group P−6m2), and the stacking-fault structure was observed in the crystal lattice. The weak CDW transition at TCDW∼43K thermodynamically is of second order.

Here, pristine and Pd-intercalated 2H−TaS2 single crystals with (00l) orientation were grown by the chemical vapor transport technique. The superconductivity (SC) and charge density wave (CDW) were characterized by magnetic and electrical transport measurements. We find that SC and CDW in the pristine 2H−TaS2 condense respectively at transition temperatures Tc∼0.8K and TCDW∼78K.