Soft X-Ray Absorption Analysis in the Multi-Purpose Beamline BL10 at New SUBARU (3); Liquid Organic Compounds and Engine Oil

Abstract

Soft X-ray absorption spectra of liquid unsaturated aliphatic compounds and engine oil samples were measured at a multi-purpose beamline BL10 in NewSUBARU. Liquid samples were casted on clean gold substrates and their X-ray absorption near-edge structure (XANES) were successfully measured with a total electron yield (TEY) method under the vacuum of 10^-5 Pa. In the unsaturated aliphatic compounds, π* and σ* peaks which depend on the length of alkyl substituents can be clearly observed. In the deteriorated engine oil samples, anti-oxidizing agents disappeared and alkyl chains were formed by opening the C=C double bonds. It is therefore confirmed that liquid organic samples can be analyzed by soft X-ray absorption spectroscopy in BL10/NS.