10) Formation of Glass Microspheres under High Magnetic Field

Formation of glass microspheres by an evaporation-condensation process is investigated under high magnetic fields. An Na2O-2TeO2 glass was evaporated by CO2 laser light under a strong gradient of a magnetic field (23T at a center of magnet HM-2). The field gradient generates repulsive magnetic force, which almost cancels out gravitational force. A cloud of glass microspheres spread out around the fixed glass source under the field gradient, while it flowed upward by thermal convection under a zero field. The size of the microspheres produced under the high field was smaller than that produced under the zero field. We found that sodium content in telluride vapor can be controlled by using high magnetic field, resulting in the decrease of size and the increase of sodium concentration of microspheres.

Photonics Research Institute, Kansai-Center, AIST : Naoyuki Kitamura IMR, Tohoku University : Iwao Mogi, Satoshi Awaji, Kazuo Watanabe, Mitsuhiro Motokawa Reference : N. Kitamura, M. Makihara, T. Sato, M. Hamai, I. Mogi, S. Awaji, K. Watanabe, M. Motokawa, "Glass spheres produced under high magnetic field", J. Non-Crystal. Solids 293-295 (2001) 624-629.