The solution approach was employed to yield multifunctional amorphous Gd2O(CO3)2 · H2O colloidal spheres by reflux of an aqueous solution containing GdCl3 · 6H2O and urea. By elongating the reaction time, crystalline rhombus‐ shaped Gd2O(CO3)2 · H2O with at least 87% yield could be formed and were also accompanied by some rectangular particles. High‐resolution synchrotron powder X‐ray diffraction provides crystal structure information, such as cell dimensions, and indexes the exact crystal packing with hexagonal symmetry, which is absent from the Joint Committee on Powder Diffraction Standards file, for the crystalline rhombus sample. Particle formation was studied based on the reaction time and the concentration ratio of [urea]/[GdCl3 · 6H2O]. After a calcination process, the amorphous spheres and crystalline rhombus Gd2O(CO3)2 · H2O particles convert into crystalline Gd2O3 at temperatures above 600 °C. For in vitro magnetic resonance imaging (MRI), both Gd2O(CO3)2 · H2O and Gd2O3 species show the promising T1‐ and T2‐weighted effects and could potentially serve as bimodal T1‐positive and T2‐negative contrast agents. The amorphous Gd2O(CO3)2 · H2O contrast agent further demonstrates enhanced contrast of the liver and kidney using a dynamic contrast‐enhanced MR imaging (DCE‐MRI) technique for in vivo investigation. The multifunctional capability of the amorphous Gd2O(CO3)2 · H2O spheres was also evidenced by the formation of nanoshells using these amorphous spheres as the template. Surface engineering of the amorphous Gd2O(CO3)2 · H2O spheres could be performed by covalent bonding to form hollow silica nanoshells and hollow silica@Fe3O4 hybrid particles.

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The crystal structure of Gd(CO3)OH was solved using synchrotron powder X‐ray diffraction. Gd(CO3)OH was known to exist in a form Gd2O(CO3)2·H2O and its powder pattern has been listed in JCPDF (#430604) for decades, but the crystal structure has not yet been elucidated. The crystal structure is solved with simulated annealing and the DASH program. The final Rietveld refinement converged to Rwp =6.28%, Rp = 4.47%and χ2 = 1.348, using the GSAS program. Gd(CO3)OH crystallizes in orthorhombic system with lattice parameters a = 7.08109(9), b = 4.88436(7), c = 8.45010(13)Å and space group P nma. Gd(CO3)OH forms a three‐dimensional framework with an eight‐membered ring, a one‐dimensional channel and OH− in the cavity. XANES of Gd LIII‐edge indicates that the oxidation state of Gd is 3+. Two phase transitions of Gd(CO3)OH were found at 500 and 650 °C to yield Gd2O2CO3 and Gd2O3 respectively.

Page s 114 isotope is concerned and deuteration is unfeasible (true for many materials, e.g. hydrogen storage materials, proton conductors, ferroelectrics, etc.). Improvements in neutron and detector technology have changed this long-standing view and a range of hydrogenous materials have now been characterised successfully with PND. [1-6] There are limitations though, naturally dependent on the 1 H content, complexity and thermal motion of the material under study. The general reduction of information inherent in PND data (from both the nature of the powder data and the often high incoherent background contribution from hydrogen-containing materials) can be partially overcome by the inclusion of single crystal X-ray diffraction (SXD) data in joint PND and SXD refinements. Also, imaging proton densities from difference Fourier maps is an old but equally powerful tool to obtain qualitative information about proton behaviour. We intend to show what appears possible today, but also point out the limitations we have found on the basis of recent datasets collected at the high intensity powder diffractometer D20 at ILL, Grenoble, and the recently upgraded HRPD at ISIS, UK. The materials studied include both inorganic and organic, and vary in 1 H content, complexity and data collection temperature.