NMR Study of 181Ta in the Commensurate Charge-Density-Wave State of 1T-TaSe2 and 1T-TaS2 Single Crystals: A Microscopic Investigation of the Three-Dimensional Ordering of the Charge Density Waves

The 181 Ta NMR in 1 T -TaSe 2 and 1 T -TaS 2 has been studied at 4.2 K using a single-crystal specimen in order to obtain detailed information on the three-dimensional ordering of the charge density waves. The experimental results indicate that the stacking of the charge density waves is quite different between 1 T -TaSe 2 and 1 T -TaS 2 .