Work

Impact of graphite and alumina ceramic thermal insulation on the growth of undoped sapphire plates by micro-pulling down

Year: 2025

Type: article

Abstract: Undoped sapphire plates were grown by the micro-pulling down technique from Mo crucibles, and the use of graphite and alumina ceramics thermal insulation was evaluated . Through the use of these two thermal insulations, the bubbles encapsulated in the plates were analyzed both qualitatively and in terms of their distribution. By comparing with plates grown from Ir crucibles, it is shown that growing sapphire plates from Mo crucibles in graphite thermal insulation results in the best quality, including a more favorable bubble distribution and fewer particle inclusions. It is evaluated that the critical factor is to avoid any source of oxygen in the chamber, as this highly influences the state of the Mo crucible and thereby the sapphire crystals.

Source: Materials Research Bulletin

DOI: 10.1016/j.materresbull.2025.113846

Authors: Laura Wollesen, Abdeldjelil Nehari, Serge Labor, Guillaume Alombert-Goget, Denis Guignier, Kheirreddine Lebbou

Institutions: Lyon 1 Université, Centre National de la Recherche Scientifique, Institut Lumière Matière

Language: English

Topic: Advanced ceramic materials synthesis

Subfield: Ceramics and Composites

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,610

Funders: Université Claude Bernard Lyon 1, Conseil National de la Recherche Scientifique, Région Auvergne-Rhône-Alpes, European Regional Development Fund