Temporal Evolution of Diffusion Barriers Surrounding ZrTiO4 Nuclei in Lithia Aluminosilicate Glass-Ceramics

• Published in: Crystal growth & design 2012-03, Vol.12 (3), p.1556-1563
• Main Authors: Höche, Thomas, Patzig, Christian, Gemming, Thomas, Wurth, Roman, Rüssel, Christian, Avramov, Isak
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nucleation; Physics; Solid-solid transitions; Specific phase transitions
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg2016148

Glasses are usually synthesized by quenching a melt rapidly enough to avoid crystallization. Nanocrystalline materials can subsequently be derived from glasses by controlled crystallization with applying a tailored heat treatment. Upon the latter, nucleation agents are widely used to adjust the desired nanostructures. Nano glass-ceramics often possess intriguing properties. For example, they can be ultratransparent; that is, they hardly scatter light or possess thermal expansion coefficients very close to zero. Such properties have a high potential for future applications in optical devices. In this paper, the role of zirconia and titania used as nucleation agents in a lithia aluminosilicate glass is studied on the nanoscale using cutting edge analytical and imaging techniques performed using the transmission electron microscope. Precipitation of ZrTiO4 nanocrystals [Bhattacharyya, S., et al. Nano Lett. 2009, 9, 2493 ] was found earlier to be accompanied by the formation of a circumjacent diffusion barrier consisting of alumina. In addition to this, here we study the temporal evolution of the alumina barrier and the size distributions of ZrTiO4 nanocrystals and lithia aluminosilicate high-quartz solid solution crystals promoted by the nucleation agent. In the light of these findings, the theory of self-limited growth is refined.