Application of Soft X-ray Microspectroscopic Analyses to Architectural Structures – a Case Study on Ceramic-Tile/adhesive/mortar-structured Composite Materials

Synchrotron radiation (SR)-based soft X-ray (SX) microspectroscopy has been applied as a promising analytical method to investigate architectural structures that comprise ceramic-tile/adhesive/mortar-structured composite materials. Microprobe X-ray fluorescence (mu XRF) spectra, elemental distribution maps and microprobe near-edge X-ray absorption fine structure (mu NEXAFS) spectra were observed near each interface in the composite materials using an SX-beam with a beam size of 1-2 mu m full-width at half-maximum (FWHM). Elemental distribution maps for O, Na, Mg, Al, and Si were obtained to clearly visualize the interfaces of the composite materials with pixel sizes of 10 and 1 mu m with the aid of line profile analyses. When the photon flux of the focused SX-beam reached approximately 8 x 10(8) ph/s, the critical dose time (t(dose)(c)) for the adhesive was estimated to be 30 min (t(dose)(c) is the time at which the peak intensity of a specific chemical state in the mu NEXAFS spectrum decreases to 1/e of the initial undamaged state due to radiation damage). We demonstrated the capability of the proposed method to survey local information regarding element-specific chemical states at the ceramic-tile/adhesive and adhesive/mortar interfaces before the adhesive is severely damaged due to the intense SX-beam.