Structural Characterization of Na0.96Ho9.04(SiO4)6Cl0.02O1.98 Apatite Prepared by Mechanical Milling

• Published in: Journal of chemical crystallography 2010-04, Vol.40 (4), p.323-327
• Main Authors: Rosales, Ivonne, Orozco, Eligio, Bucio, Lauro, Fuentes, Maria E., Fuentes, Luis
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Crystallography and Scattering Methods; Inorganic Chemistry; Organometallic Chemistry; Original Paper; Physical Chemistry
• ISSN: 1074-1542; 1572-8854
• DOI: 10.1007/s10870-009-9655-4

In this paper we report the synthesis and structural characterization of Na 0.96 Ho 9.04 (SiO 4 ) 6 Cl 0.02 O 1.98 apatite prepared by mechanical milling at room temperature, in which well crystallized sample was obtained after heating the sample at 1123 K. The crystal structure study was carried out by synchrotron radiation diffraction. This apatite crystallizes in the hexagonal space group P6 3 /m (No. 176) with cell parameters a  = 9.3444(1) Å, c  = 6.7611(1) Å, unit cell volume of 511.27(1) Å 3 and Z  = 1. As in other rare-earth orthosilicate apatites, it was found that sodium cations are mixed with holmium occupying the 4 f position at the center of tricapped trigonal prisms; while holmium fully occupies the 6 h position at the center of a seven-coordinated polyhedron. No vacancies are present in the two crystallographic sites available for holmium atoms. The chemical composition was established by wavelength dispersive spectroscopy. Graphical Abstract The title compound, Na 0.96 Ho 9.04 (SiO 4 ) 6 Cl 0.02 O 1.98 was synthesized by mechanical milling at room temperature and well crystallinity was obtained after heating the sample at 1123 K. X-ray powder diffraction analysis reveals that sodium cations in the crystal structure, are mixed with holmium occupying one of the crystallographic sites.