Annual Review 2024-2025

S P E C T R O S C O P Y G R O U P A N N U A L R E V I E W 2 0 2 4 / 2 5 28 is equipped with a multi-element germanium detector that enables the structural study of low concentration samples in fluorescence detection mode. The XES end-station is based on a 1m Rowland circle point-to-point spectrometer and is used to perform High-Energy-Resolution Fluorescence Detection XAS (HERFD-XAS) and resonant and non-resonant X-ray Emission Spectroscopy (RXES and XES) to study the electronic structure of materials. SWIFT (Spectroscopy WithIn Fast Timescales) will be a wiggler-based, quick-scanning EXAFS beamline dedicated to operando studies, also at micrometric scale. The construction of the SWIFT hutches is progressing well, some of the main optical components have already been ordered, and the design of the challenging fast monochromator is well advanced. The beamline will become operational on Diamond-II after the upgrade period. Modelling glass long term corrosion using naturally altered archaeological glasses Lead silicate glass ingots from the East Indiaman sailing vessel the Albion, sunk off Margate UK in 1765 and recovered from the wreck in 1985, were studied to ascertain the chemistry and mineralogy of alteration products after exposure to seawater for 220 years. The results were compared to those of the same glasses exposed to short-term, high temperature, laboratory dissolution tests in synthetic seawater. The research team from the Universities of Sheffield, Bristol, Essex and Cologne used X-ray Absorption Near Edge Structure (XANES) spectroscopy on beamline I18 to study the local coordination environment and speciation of elements within these layers, particularly iron (Fe), calcium (Ca), and phosphorus (P). The XANES results highlighted significant differences between natural and laboratory-altered samples. In natural samples, Fe accumulated to form Fe- silicates, while in laboratory tests, Mg-silicates predominated due to limited Fe availability. Similarly, natural samples showed the formation of Pb- substituted apatite phases, influenced by the continuous supply of PO₄³ - from the open seawater system, unlike the Pb-sulphate phases formed in laboratory conditions. These findings underscore the importance of considering minor elements and biological activity in long-term corrosion studies, as they significantly impact the alteration processes and the resulting mineral phases. The study demonstrates the challenges in replicating complex natural systems in laboratory settings and the need for more realistic simulations to predict the long-term behaviour of materials. DOI: 10.1016/j.apgeochem.2025.106363 A) Location of Ca K-edge XANES spot analysis on μXRF map of Ca. B) Ca K-edge XANES spectra of Ca-bearing mineral phases and C) Ca K-edge XANES spectra of Ca rich spots. B C A Energy (eV) Energy (eV) Relative Intensity