Structural and chemical bonding changes in nuclear graphite have been investigated during in-situ electron irradiation in a transmission electron microscope (TEM); electron beam irradiation has been employed as a surrogate for neutron irradiation of nuclear grade graphite in nuclear reactors. This paper aims to set out a methodology for analysing the microstructure of electron-irradiated graphite which can then be extended to the analysis of neutron-irradiated graphites. The damage produced by exposure to 200 keV electrons was examined up to a total dose of approximately 0.5 dpa (equivalent to an electron fluence of 5.6x 10 21 electrons cm -2 ). During electron exposure, high resolution TEM images and electron energy loss spectra (EELS) were acquired periodically in order to record changes in structural (dis)order and chemical bonding, by quantitatively analysing the variation in phase contrast images and EEL spectra.

Thermal decomposition of crystalline struvite provides an efficient and well controllable method for the synthesis of mesoporous phosphates.

Calcium sulfate minerals are found in nature as three hydrates: gypsum (CaSO4·2H2O), bassanite (CaSO4·0.5H2O), and anhydrite (CaSO4). Due to their relevance in natural and industrial processes, the formation pathways of calcium sulfates from aqueous solution have been the subject of intensive research and there is a growing body of literature, suggesting that calcium sulfates form through a nonclassical nanoparticle-mediated crystallisation process. We showed earlier (Stawski et al. 2016) that at the early stages in the precipitation reaction, calcium sulfate nano-crystals nucleate through the reorganization and coalescence of aggregates rather than through classical unit addition. Here, we used low-dose dark field (DF) transmission electron microscopy (TEM) and electron diffraction and document that these re-structuring processes do not continue until a final near-perfectly homogeneous single crystal is obtained. Instead we show that the growth process yields a final imperfect mesocrystal with an overall morphology resembling that of a single crystal, yet composed of smaller nano-domains.Our data reveal that organic-free calcium sulfate mesocrystals grown by a particle mediated-pathway may preserve in the final crystal structure a "memory" or "imprint" of their non-classical nucleation process, something that has been overlooked until now. Furthermore, the nano-scale misalignment of the structural sub-units within these crystals might propagate through the length-scales, which is potentially be expressed macroscopically as misaligned zones/domains in large single crystals. This is akin to observations in some of the giant crystals from the Naica Mine, Chihuahua, Mexico.