CHARGE-DENSITY WAVES IN 1T-TAS2 - AN EXAFS STUDY

Two polytypes (2H- and 1T-) of TaS2 have been investigated by extended X-ray absorption fine structure (EXAFS) spectroscopy. The EXAFS data were in good agreement with the trigonal-prizmatic coordination of Ta in 2H-TaS2. For 1T-TaS2, a lattice distortion of Ta local surrounding was observed, attributed to charge density waves (CDW). In order to fi t the EXAFS data, a new model of the CDW cluster has been suggested wh ich includes both the Ta and S atoms' displacements. (C) 1998 Elsevier Science B.V. All rights reserved.