caa a22 4500 463227751 CHVBK 20180405153232.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10853-007-1979-x doi (NATIONALLICENCE)springer-10.1007/s10853-007-1979-x Crystallization of CaHf1− x Zr x Ti2O7 (0≤ x ≤1) zirconolite in SiO2-Al2O3-CaO-Na2O-TiO2-HfO2-ZrO2-Nd2O3 glasses [Elektronische Daten] [Daniel Caurant, Isabelle Bardez, Pascal Loiseau] Glass-ceramics containing (Hf,Zr)-zirconolite crystals (nominally CaHf1−x Zr x Ti2O7 with 0≤x≤1) were envisaged to immobilize minor actinides and plutonium. Such materials were prepared in this study by controlled crystallization of glasses belonging to the SiO2-Al2O3-CaO-Na2O-TiO2-HfO2-ZrO2-Nd2O3 system. Neodymium was used as trivalent actinides surrogate. The effect of total or partial substitution of ZrO2 by HfO2 (neutron poison for fission reactions) on glass crystallization in the bulk and near the surface is presented. It appeared that Hf/Zr substitution had not significant effect on nature, structure, and composition of crystals formed both on glass surface (titanite+anorthite) and in the bulk (zirconolite). This result can be explained by the close properties of Zr4+ and Hf4+ ions and by their similar structural role in glass structure. However, strong differences were observed between the nucleation rate IZ of zirconolite crystals in glasses containing only HfO2 and in glasses containing only ZrO2. Hf-zirconolite (CaHfTi2O7) crystals were shown to nucleate only very slowly in comparison with Zr-zirconolite (CaZrTi2O7) crystals. Composition changes - by increasing either HfO2 or Al2O3 concentration or by introducing ZrO2 in parent glass - were performed to increase IZ in hafnium-rich glasses. The proportion of Nd3+ ions incorporated in the zirconolite phase was estimated using ESR. 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 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 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 Journal of Materials Science Springer US; http://www.springer-ny.com 42/24(2007-12-01), 10203-10218 0022-2461 42:24<10203 2007 42 10853 https://doi.org/10.1007/s10853-007-1979-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1979-x 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- 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- 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 773 0- Journal of Materials Science Springer US; http://www.springer-ny.com 42/24(2007-12-01), 10203-10218 0022-2461 42:24<10203 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer