Solvothermal methods

Hydrothermal/solvothermal methods are used by several groups, who develop and share specific autoclaves. The hydrothermal method is used for crystal engineering of metal iodates, that are promising materials for the realization of optical parametric amplifiers and oscillators in the IR range until 12 µm. This method leads to original phases and allows to control the rate of insertion of rare earths in many phases as La(IO3)3, AgGd(IO3)4 or Y(IO3)3 (MatONLP – MCMF group).

[bleu marine]RE-doped Metal Iodate (left) and Single crystal of In(IO3)3 (right)[/bleu marine]

The hydrothermal technique is also used to grow hydroxyhalides, especially of the atacamite family Cu3M(OH)6Cl2, a rare example of perfectly planar Kagome network of Cu2+ for frustrated magnetism studies of S = ½ systems (SPMCE - MCMF group).

[bleu marine] Single crystals of atacamite Cu3Zn(OH)6Cl2[/bleu marine]

The chemical reactivity of aqueous solutions under hydrothermal conditions is studied through in situ synchrotron X-ray and optical Raman spectroscopies. The physico-chemistry properties of supercritical fluids (hydrogen bonding, solvation properties, nature of radicals), mostly H2O and CO2, and the speciation of dissolved metal in hydrothermal conditions have important implications for metal transport and petrology, fluid-rock interactions and CO2 storage. All these experiments are based on the development of high pressure-high temperature set-ups (strong expertise in high pressure within the MCMF department). A recent application of this technology is the study of the fate of organic molecules in hydrothermal conditions, in relation with the chemistry of oceanic hydrothermal vents (black smokers) (SPMCE - MCMF group)

[bleu marine]X-ray Absorption Spectroscopy (CRG-FAME, ESRF) and use of a high-pressure autoclave.[/bleu marine] [bleu marine]Monitoring of Fe solubility and Short range order, both derived from the analysis of X-ray absorption spectra.[/bleu marine]

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