Journal of Materials Science and Chemical Engineering, 2018, 6, 151-162 http://www.scirp.org/journal/msce ISSN Online: 2327-6053 ISSN Print: 2327-6045 DOI: 10.4236/msce.2018.67016 Jul. 31, 2018 151 Journal of Materials Science and Chemical Engineering Lanthanum-Neodymium-Co-Substituted Calcium Fluorobritholites Mustapha Hidouri 1,2 , Nawaf Albeladi 3 1 Higher Institute of Applied Sciences and Technology of Gabes, Gabes University, Gabes, Tunisia 2 RU Catalysis and Materials for Environment and Process, Engineering School, Gabes University, Gabes, Tunisia 3 Chemistry Department, Faculty of Sciences Yanbu, Taibah University, Yanbu Al Bahr, KSA Abstract Britholites are considered as potential matrices for storage of nuclear wastes such as minor actinides and long-lived fission byproducts. This investiga- tion is concerned with the study of simultaneous substitution in calcium fluor-britholite framework of two lanthanide ions assimilated to radionuc- lides. A series of calcium fluorbritholites doped with lanthanum and neo- dymium Ca 8 La 2−x Nd x (PO 4 ) 4 (SiO 4 ) 2 F 2 with 0 ≤ x ≤ 2 were prepared via a solid state reaction in the temperature range 1450˚C - 1250˚C. The obtained prod- ucts were characterized by several techniques such as Chemical analysis via Inductively coupled plasma Atomic emission spectrometry ICP-AES, X-ray diffraction (XRD), Fourier transformed infra-red spectroscopy FTIR and Nuclear magnetic resonance 31 P NMR (MAS). Obtained solid solutions con- taining lanthanum and neodymium in variable proportions were typically apatite of hexagonal structure P63/m spatial group. The stoichiometry of the powders was verified via the metal/(phosphate + silicate) molar ratios found at about 1.67. The lattice parameters a and c calculated by the Rietveld me- thod decreased as neodymium level increased. Despite, the close respective sizes of lanthanum and neodymium ions ( VI r La3+ = 1.032Å, VI r Nd3+ = 0.983Å), their mutual substitutions led to solid solutions in whole range of composi- tion with preferential occupation of Me (2) sites. Keywords Calcium Fluorobritholites, Lanthanum-Neodymium, Ionic Substitutions 1. Introduction Over the last decades, apatites of general formula Me 10 (XO 4 ) 6 Y 2 with Me a diva- lent cation, XO 4 a trivalent anion and Y a monovalent anion have acquired an How to cite this paper: Hidouri, M. and Albeladi, N. (2018) Lanthanum-Neody- mium-Co-Substituted Calcium Fluorobri- tholites. Journal of Materials Science and Chemical Engineering, 6, 151-162. https://doi.org/10.4236/msce.2018.67016 Received: February 16, 2018 Accepted: June 10, 2018 Published: July 31, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access