Hybrid electrostatic-aerodynamic levitation furnace for the high-temperature processing of oxide materials on the ground

This article describes a hybrid electrostatic-aerodynamic levitation furnace for the containerless processing and study of oxide materials on the ground. Its operation principle relies on an aerodynamic levitator that allows sufficient electric charge to be accumulated on a sample, due to high-temperature heating, before electrostatic levitation can be effective. The article discusses the concept of this new levitator and presents the proof of the technical feasibility of electrostatically levitating and melting oxide material samples (BiFeO3, 49.5CaO-50.5Al(2)O(3) mol %) in a pressurized atmosphere. In addition, superheating-undercooling cycles can be performed while maintaining an exceptional sample positioning stability along the three directions. Moreover, we report the first vitrification of dielectric oxide material samples (49.5CaO-50.5Al(2)O(3) mol %) using an electrostatic levitation method. The article also discusses the advantages of this facility compared with other existing instruments for the containerless processing of oxide materials, in particular, with respect to molten sample position stability and hydrodynamic quietness, long duration levitation times, and open field of view of the sample. The facility is, in its current state, capable of novel glass synthesis. Moreover, it shows great promise for structural and thermophysical properties characterization and metastable phase studies when supplemented with the appropriate diagnostic tools. The demonstration of melting and vitrifying oxide material is also a corner stone for the design of a containerless research facility in microgravity. (C) 2001 American Institute of Physics.