Thickness dependence of the charge-density-wave transition temperature in VSe2.

A set of three-dimensional charge-density-wave (3D CDW) VSe₂ nano-flakes with different thicknesses were obtained by the scotch tape-based micro-mechanical exfoliation method. Resistivity measurements showed that the 3D CDW transition temperature T_p decreases systematically from 105 K in bulk to 81.8 K in the 11.6 nm thick flake. The Hall resistivity ƿ_xy of all the flakes showed a linear dependent behavior against the magnetic field with a residual electron concentration of the order of ~10²¹cm^-3 at 5K. The electron concentration n increases slightly as the thickness d decreases, possibly due to the CDW gap is reduced with the decrease of the thickness. [ABSTRACT FROM AUTHOR]