The Containerless Synthesis of Glass

Glasses are commonly synthesized by cooling melts at a rate sufficient to prevent the nucleation of substantial amounts of crystalline phases. In the limit, high cooling rates no longer prevent crystallization. In some of these cases, elimination of container-melt-induced nucleation by using containerless processing (also called levitation) significantly extends the glass-forming composition range. Containerless methods also eliminate contamination allowing the preparation of high-purity materials that can be used to benchmark properties and structure. This article briefly reviews the application of containerless methods to several types of glass. Some examples of glasses formed using containerless techniques are presented and discussed in the context of developing materials. A short commentary on specific issues that relate to the use of containerless processing is presented. This review is intended to provide an introduction to the use of containerless methods in glass research.