Glass spheres produced by magnetic levitation method

Melting of glass levitated in high magnetic fields has been performed by using a hybrid magnet and a CO2 laser. A sphere of an optical glass (BK7) has been obtained through melting and cooling without any crucible. Raman scattering and electron spin resonance (ESR) of the glass sphere showed no spatial anisotropy with respect to the applied field. Microspheres of binary sodium tellurite glass were also obtained for the first time by an evaporation–condensation process in high magnetic fields. Thermal convection was suppressed under a magnetic force of −0.8g. The size of microspheres produced under the magnetic force was about 500 nm at most. This size is one-half the size of spheres produced without a magnetic field. Raman scattering measurements on microspheres produced under the magnetic field showed different spectra from those without a magnetic field. The difference is due to a deficiency of sodium ions in the spheres produced without a magnetic field.