Na and Cl₂ Interaction on it and 2H–TaSe₂(0001) Surfaces

Abstract

In this paper we study the interaction of Cl2 and Na on 1T-TaSe2 and 2H-TaSe2(0001) surfaces in the temperature range of 100-300 K. The experiments are performed in UHV with the use of LEED and SXPS by synchrotron radiation measurements. Deposition of Na on Cl2-covered 1T-TaSe2 at 100 K forms initially a Na-Cl − 2 , which with increasing temperature to 300 K leads to NaCl formation. Adsorption of Cl2 on Na-intercalated 1T and 2H-TaSe2 surfaces at 100 K forms Cl2 multilayers. The first Cl2 layer, in contact with the substrate, interacts with the Na near the surface and forms Na-Cl − 2 . Warming up to 300 K leads to partial desorption of Cl2, while the remaining chlorine interacts strongly with Na, causing the deintercalation of Na to the surface in the tendency to form NaCl. The intercalation-deintercalation process takes place across the van der Waals planes and it is much faster on 2H than on 1T-TaSe2, which is attributed to the different crystal structure of 2H and 1T of TaSe2.

Photoemission from Intercalated Transition Metal Dichalcogenides

“…Deposition of Na at 100 K after exposure and subsequent warming to 300 K resulted in NaCl formation without intercalation. In a similar study, Papageorgopoulos et al [56] found that the induced de-intercalation of Na was much faster on 2H-than on In a TEM study by Remškar et al [76] it was observed that prolonged exposure of Cs intercalated to air resulted in de-intercalation and growth of on the surface, predominantly where the surface was cracked. …”