Тип публикации: статья из журнала
Год издания: 2018
Идентификатор DOI: 10.1016/j.carbon.2018.02.106
Аннотация: We report the scanning tunneling microscope (STM) observation of the Li+ ion endohedral C-60 on Cu(111), prepared by means of evaporation of a high-purity Li+@C-60[PF6-%salt. The electronic state of Li+@C-60 in the Li+@C-60[PF6-%salt was also determined using photoemission and X-ray absorption spectroscopy, along with the density fПоказать полностьюunctional theory (DFT) calculations. In the salt, Li and PF6 had nearly single positive and negative charge, respectively; thus the C-60 cage was practically neutral. The salt decomposed under ultra-high vacuum while heating at 400 degrees C. This allowed the selective deposition of Li+@C-60 on Cu(111). Although secondary-ion mass spectroscopy of the deposited Li+@C-60 film showed a decrease in the Li-content during evaporation, Li+@C-60 was successfully identified using STM. The DFT calculations of Li+@C-60 on Cu(111) suggested that the Li+ ion was singly charged and the location of the Li+ ion was displaced in an upward direction, which altered the local density of states in an upper section of C-60, especially for LUMO+2. The calculated results were mostly in agreement with the bias-dependent STM and dI/dV images. However, an inconsistency was observed between the calculation and experiments in case of empty state imaging where tip-induced displacement of the Li+ ion may occur. (C) 2018 Published by Elsevier Ltd.
Журнал: CARBON
Выпуск журнала: Vol. 133
Номера страниц: 23-30
ISSN журнала: 00086223
Место издания: OXFORD
Издатель: PERGAMON-ELSEVIER SCIENCE LTD