• 文献标题:   Soft X-ray Exposure Promotes Na Intercalation in Graphene Grown on Si-Face SiC
  • 文献类型:   Article
  • 作  者:   WATCHARINYANON S, XIA C, NIU YR, ZAKHAROV AA, JOHANSSON LI, YAKIMOVA R, VIROJANADARA C
  • 作者关键词:   graphene on siface sic, intercalation of na, soft xray exposure, electron exposure
  • 出版物名称:   MATERIALS
  • ISSN:   1996-1944
  • 通讯作者地址:   Linkoping Univ
  • 被引频次:   1
  • DOI:   10.3390/ma8084768
  • 出版年:   2015

▎ 摘  要

An investigation of how electron/photon beam exposures affect the intercalation rate of Na deposited on graphene prepared on Si-face SiC is presented. Focused radiation from a storage ring is used for soft X-ray exposures while the electron beam in a low energy electron microscope is utilized for electron exposures. The microscopy and core level spectroscopy data presented clearly show that the effect of soft X-ray exposure is significantly greater than of electron exposure, i.e., it produces a greater increase in the intercalation rate of Na. Heat transfer from the photoelectrons generated during soft X-ray exposure and by the electrons penetrating the sample during electron beam exposure is suggested to increase the local surface temperature and thus the intercalation rate. The estimated electron flux density is 50 times greater for soft X-ray exposure compared to electron exposure, which explains the larger increase in the intercalation rate from soft X-ray exposure. Effects occurring with time only at room temperature are found to be fairly slow, but detectable. The graphene quality, i.e., domain/grain size and homogeneity, was also observed to be an important factor since exposure-induced effects occurred more rapidly on a graphene sample prepared in situ compared to on a furnace grown sample.