caa a22 4500 463223594 CHVBK 20180405153220.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10853-007-1810-8 doi (NATIONALLICENCE)springer-10.1007/s10853-007-1810-8 Effect of Al2O3 concentration on zirconolite (Ca(Zr,Hf)Ti2O7) crystallization in (TiO2,ZrO2,HfO2)-rich SiO2-Al2O3-CaO-Na2O glasses [Elektronische Daten] [Daniel Caurant, Pascal Loiseau, Isabelle Bardez, Christel Gervais] Glass-ceramic matrices containing zirconolite (nominally Ca(Zr,Hf)Ti2O7) crystals in their bulk that would incorporate high proportions of minor actinides (Np, Am, Cm) or plutonium could be envisaged for their immobilization. Zirconolite-based glass-ceramics can be prepared by controlled crystallization of zirconolite in glasses belonging to SiO2-Al2O3-CaO-Na2O-TiO2-ZrO2-HfO2 system. In this study, neodymium was used as trivalent actinides surrogate. Increasing Al2O3 concentration in glass composition had a strong effect on the nucleation rate I z of zirconolite crystals in the bulk, on the amount of neodymium incorporated in zirconolite phase and on the crystal growth rate of silicate phases (titanite+anorthite) from glass surface. These results could be explained by the existence of competition—in favor of aluminum—between Al3+ and (Ti4+, Zr4+, Hf4+) ions for their association with charge compensators cations to facilitate their incorporation in the glassy network. Differential thermal analysis (DTA) was used to study exothermal effects associated with bulk and surface crystallization. 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra showed that aluminum enters glasses network predominantly in 4-fold coordination. Neodymium optical absorption and fluorescence spectroscopies showed that the Al2O3 concentration changes performed in this study had not significant effect on Nd3+ ions environment in glasses. Springer Science+Business Media, LLC, 2007 Caurant Daniel Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut Loiseau Pascal Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut Bardez Isabelle Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut Gervais Christel Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Université Pierre et Marie Curie, 4 Place Jussieu, 75252, Paris, France aut Journal of Materials Science Springer US; http://www.springer-ny.com 42/20(2007-10-01), 8558-8570 0022-2461 42:20<8558 2007 42 10853 https://doi.org/10.1007/s10853-007-1810-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1810-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Caurant Daniel Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut NATIONALLICENCE 700 1- Loiseau Pascal Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut NATIONALLICENCE 700 1- Bardez Isabelle Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Ecole Nationale Supérieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231, Paris, France aut NATIONALLICENCE 700 1- Gervais Christel Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, Université Pierre et Marie Curie, 4 Place Jussieu, 75252, Paris, France aut NATIONALLICENCE 773 0- Journal of Materials Science Springer US; http://www.springer-ny.com 42/20(2007-10-01), 8558-8570 0022-2461 42:20<8558 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer