Structure of soda-lime-aluminosilicate glasses as revealed by in-situ synchrotron powder diffraction experiments

The atomic structure of a soda-lime-aluminosilicate network glass that underwent two different thermal treatments has been investigated by in-situ Synchrotron Powder Diffraction experiments in the 30–1000 ∘C temperature range. First Sharp Diffraction Peak analysis has been initially performed to investigate intermediate range order characteristics: it provided information on volume variations upon heating and cooling, and final relaxation level as a function of the different thermal treatment. Pair Distribution Function analysis has been performed by Empirical Potential Structure Refinement modeling: it pointed out the short range order peculiarities of the samples. In particular, the thermal expansion behaviour of different atomic pairs has been revealed, together with a wide range of structural features like coordination numbers and polymerization degree. The present work well describes the multiple over temperature phenomenology of the investigated composition and discloses how the local range behaves independently from the thermal history of the sample.