Contribution of neodymium optical spectroscopy to the crystal growth study of a silicate apatite in a glassy matrix

• Published in: Optical materials Vol. 30; no. 11; pp. 1694 - 1698
• Main Authors: de Ligny, D., Panczer, G., Caurant, D., Neuville, D.R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2008; Elsevier Science
• Subjects: Amorphous materials, glasses and other disordered solids; Borosilicate; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Glass–ceramic; Nuclear waste glasses; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Rare-earth ions; Visible and ultraviolet spectra; 81.05.Pj; Borosilicate; 64.60.Qb; 78.40.−q; 78.55.−m; Nuclear waste glasses; Glass–ceramic; Rare-earth ions; 61.43.Fs; Crystal growth; 78.55.-m; Nucleation; 78.40.-q; Crystallization; Doped materials; Ceramics; Silicates; Heat treatments; Borosilicate glass; Glass-ceramic; Emission spectra; Neodymium additions; Optical properties; Apatites; Absorption spectra
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2007.07.008

Neodymium migration from the glass to the unique crystal phase, Ca 2Nd 8(SiO 4) 6O 2 apatite, was followed by absorption ( 4I 9/2 → 2P 1/2 transition) and emission ( 4F 3/2 → 4I 9/2 transition) spectroscopy in aluminoborosilicate glass–ceramics prepared at various temperatures. Comparison of these glass–ceramics showed that ordering of Ca 2+ and Nd 3+ ions in the 6h and 4f sites of the silicate apatite structure progressively increased when the crystallisation temperature T c is raised from 950 to 1450 K. Taking advantage of the emission quenching in apatite crystals due to high Nd 3+ ions concentration, the residual glass surrounding these crystals was probed. The highest neodymium depletion in the glassy phase was obtained after heat treatment at T c = 1300 K. Neodymium was found to be a nucleation agent for apatite crystallization. The nucleation mechanism of this phase at low temperature begins by the migration of Nd 3+ ions from glass sites to the apatite 4f sites that are structurally close. At higher temperature, due to the increasing thermal energy available during crystal growth, the proportion of Nd 3+ ions incorporated in the apatite 6h site increased.