Synthesis of Sodium-Lead Apatite Structure with the Excess and the Lack of Sodium

Mohammed A. B. Abdul Jabar

doi:10.24996/ijs.2023.64.5.2

Authors

Mohammed A. B. Abdul Jabar Department of forensic Science, College of Science, Al-Karkh University of Science, Baghdad, Iraq https://orcid.org/0000-0001-7891-5444

DOI:

https://doi.org/10.24996/ijs.2023.64.5.2

Keywords:

Lead, Apatite, Isomorphic substitutions, Solid solution

Abstract

X-ray phase analysis was used to analyse the composition of Pb₈Na_(2±x)(PO₄)₆ (lead-sodium apatite structure) with different X values (X values refer to changes in the excess or lack of sodium (2±X) in the apatite structure): -0.15, -0.10, -0.05, 0.00, +0.05, +0.10, and +0.15. The ceramic method (solid-state reaction) was used to synthesize all samples at a temperature of 800 °C. Many programs, such as match software (v.3), PDF-4 database (ICCD), and database PDF-4 (ASTM), were used to study the single phases. The least-squares method was used to calculate the unit cell parameters. Results have shown that the following compositions: Pb₈Na₂(PO₄)₆, Pb₈Na_1.95(PO₄)₆, Pb₈Na_1.90(PO₄)₆, and Pb₈Na_1.85(PO₄)₆ contain only the pure phase of lead sodium apatite structure. On the other hand, the compositions of Pb₈Na_2.05(PO₄)₆, Pb₈Na_2.10(PO₄)₆, and Pb₈Na_2.15(PO₄)₆ showed other phases besides the phases of lead sodium apatite structure.