Coherent soft X-ray standing waves in SiCl4-graphite intercalation compounds

Abstract Soft X-ray standing waves with wavelength equal to twice the distance between successive carbon layers are observed by measuring the synchrotron-radiation-pumped soft X-ray absorption spectrum of SiCl 4 -graphite intercalation compounds. It is shown that the momentum and energy transfer from incident soft X-rays to elementary excitations on intercalant layers generates the standing waves. It is suggested that SiCl 4 GIC may be a suitable substance to study the generation of coherent soft X-rays.