Near edge X-ray absorption fine structure spectroscopy (NEXAFS) is a method of investigation of material that studies fine structure near band edge [1]. This method is very useful for the investigation of carbon materials [2]. The filled single-walled carbon nanotubes (SWCNTs) is promising materials for applications in various fields, such as nanoelectronics, spintronics, biomedicine. Here, I overview the work on the investigations of filled SWCNTs with NEXAFS. I discuss trends in the spectra upon filling, modifications that testify about the changes in chemical and electronic properties [3]. New features in the spectra may testify about the formation of bonds in nanocomposites consisting from carbon nanotubes with filler inside. This is very important, complementary method for other investigation techniques of carbon material, such as Raman spectroscopy, optical absorption spectroscopy, photoemission spectroscopy. The combination of methods is important for applications of filled SWCNTs and can be used also in situ in devices.

[1] M. V. Kharlamova. Electronic properties of pristine and modified single-walled carbon nanotubes. Physics-Uspekhi 2013, 56, 1047-1073.

[2] M. V. Kharlamova. Advances in tailoring the electronic properties of single-walled carbon nanotubes. Progress in Materials Science 2016, 77, 125-211.

[3] M. V. Kharlamova et al. Inner tube growth properties and electronic structure of ferrocene-filled large diameter single-walled carbon nanotubes. Physica Status Solidi B 2013, 250, 2575-2580.