Destruction of the charge density wave structure in 1T-TaS2 under pyridine intercalation

Nanotubes from the Misfit Layered Compound (SmS)1.19TaS2: Atomic Structure, Charge Transfer, and Electrical Properties

“…The (SmS) 1.19 TaS 2 Ta L 3 “white” line intensity (3.01 ± 0.01), which corresponds to the transition from the 2 p core level to the unoccupied Ta 5 d states ( d z 2 band), is higher than the “white line” intensity value measured for pristine 2H-TaS 2 (2.75 ± 0.01). 66 , 70 Interestingly, the intercalation of pristine 2H-TaS 2 by pyridine 66 or hydrazine 70 increases the intensity of the “white line” up to the values of 2.5 and 2.9, respectively. In the case of (SmS) 1.19 TaS 2 , the charge transfer from SmS to TaS 2 would lead to a similar increase in the white line intensity of Ta L 3 in comparison with pristine 2H-TaS 2 .…”

“…The shape of the Ta L 3 XANES spectrum ( Figure 7 b) resembles the 2H-TaS 2 spectra, and the position of the “white line” at 9884 eV is close to that of the 2H-TaS 2 structure. 66 , 67 However, precise examination of the “white line” ( Figure 7 c) or the absorption edge position from the derivative of the normalized absorption ( Figure 7 d) shows that there is a small shift between 2H-TaS 2 (9881.8 ± 0.1 eV) and the (SmS) 1.19 TaS 2 (9882 ± 0.1 eV) Ta L 3 edges. It is known that the position of the Ta L 3 edge depends on the valence state of Ta: the higher the valence (oxidation state), the stronger the Ta L 3 edge shifts toward higher X-ray energies.…”

“…In general, XAS investigations show that the white line intensity grows with electron-donating intercalates and diminishes with electron-withdrawing intercalates. 66 , 70 The fundamental reason for such a change is yet to be understood.…”

“…In the case of (SmS) 1.19 TaS 2 , the charge transfer from SmS to TaS 2 would lead to a similar increase in the white line intensity of Ta L 3 in comparison with pristine 2H-TaS 2 . In general, XAS investigations show that the white line intensity grows with electron-donating intercalates and diminishes with electron-withdrawing intercalates. , The fundamental reason for such a change is yet to be understood.…”