| 摘要 |
PURPOSE:To suppress scattering of light with IR transmittable glass of a fluoride consisting of zirconium fluoride, hafnium fluoride, barium fluoride, etc. by substituting a part of the fluorine ion in the glass with borohydrofluoric acid ion. CONSTITUTION:Glass of a fluoride composed of (A) 50-70mol% zirconium fluoride and (or) hafnium fluoride, (B) 10-35mol% barium fluoride, (C) 1- 8mol% >=1 kind selected from yttrium fluoride, fluoride of lanthanoid element and thorium fluoride, (D) 0-30mol% sodium fluoride and (or) cesium fluoride and (E) 1-10mol% aluminum fluoride is produced. A part of the raw material fluoride is substd. with borohydrofluorate (e.g.; sodium borofluoride) and 0.1- 10mol% fluorine ion in the glass is substd. with borohydrofluoric acid ion, by which the intended IR transmittable glass is obtd. |
