Properties of phosphate glasses containing transition metals oxides

遷移金属酸化物を含有するリン酸塩系ガラスの物性

天本 一平; 明珍 宗孝; 矢野 哲司*; 赤木 直人*; 瀬川 浩代*; 柴田 修一*

Amamoto, Ippei; Myochin, Munetaka; Yano, Tetsuji*; Akagi, Naoto*; Segawa, Hiroyo*; Shibata, Shuichi*

鉄リン酸ガラスの組成を変化させることにより、ガラスの熱的性質,化学的耐久性にどのような影響を与えるのかについて、模擬核分裂生成物(FP)を含まないガラス、25mass%のFPを含ませたガラス、及びそれぞれでFeOの一部を遷移金属酸化物(MnO, CoO)に置換した均質なガラスを作製し、評価を行った。得られたガラスはすべて均質にガラスを形成し、熱物性(ガラス転移温度,線熱膨張係数)を正確に評価できた。化学的耐久性の実験では、FeOの置換による溶出速度の変化がFPを含む場合と含まない場合とで逆の傾向を示し、一部をCoOに置換したFP含有ガラスで化学的耐久性が高くなることがわかった。熱物性の変化や耐久性の変化がどのようにして生じたのかについては、今後、さらなる検討が必要であるが、本研究結果は、機能性の高いリン酸塩系ガラスを見いだすうえで、有用な知見となり得る。

Phosphate glasses have received much attention for the development of new low-melting glasses with low environmental load. However, their low chemical durability prevents their application for practical use. Recently, the addition of FeO was found to improve their chemical durability. Due to their high durability and high capacity of solution of dopants, iron phosphate glass system has been suggested to be utilized as new materials. In this work, the effect of the addition of other transition metal oxides on the properties of iron phosphate glass was investigated. In addition, the pseudo fission products as nuclear waste was added and their glass formation and chemical durability were investigated. All the glass batches formed homogenous melts at 1250 in the centigrade scale and vitrified without crystallization by pouring on the carbon plate. It was found that the substitution of a part of FeO by MnO or CoO did not cause large changes in the thermal properties.