紫外線によるガラスの応力発生への添加物の効果 : 遷移金属酸化物 Effects of Small Additives on Stress Build-Up in Glass by Ultra-Violet Irradiation : Transition Metal Oxides

Na2O 15, B2O3 65, SiO2 20モル%の組成のガラスに遷移族金属酸化物を添加し, 紫外線を照射して発生する応力を測定した. 添加物を効果によって分類すると, A: 少量添加では応力を増加し, ついで極大を経て1-3g/100gガラスで応力が零になる (V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Wの酸化物: なおCe, Uの酸化物も同様), B: 少量添加で応力を減らすが, かなり大量加えても零にはならない (Y, Zr, Hfの酸化物), C: 添加量とともに応力は単調に零まで減少する (Ti, Taの酸化物). 二, 三の試料について, 応力発生のための光量子エネルギーのしきい値を測ると, 5.5eV (波長220mμ) で無添加のものと同じであった. A群の場合には添加イオンの励起によって網目構造内の電子分布が変って化学結合が変化すると考えて, 添加イオンの影響を説明できる. 他種のものについては未解決である.

Soda-borosilicate glasses doped with oxides of the tratsition metals, respectively, were irradiated by Ultra-violet Light and the stresses thus caused in the lasses were measured. The effects of the oxides were elassified as follows: (A) The stress increased by small addition and then decreased to zero with increase of the concentration (B) The stress decreased by small addition and then kept low value in considerably wide concentration range, (C) The stress decreased monotonically with increase of the concentration. Threshold photon energies for the stress build-up were 5.5eV (220mμ in wavelength) or more and were the same as those of the undoped glasses. For the A group cases, the effects of the assuming excitation of the added ions additives were explained by assuming excitation of the added ions which causes rearrangement of the electrons and chemical bonds in the glass network. For the other cases, no conclusions were obtained.