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Amamoto, Ippei; Myochin, Munetaka; Yano, Tetsuji*; Akagi, Naoto*; Segawa, Hiroyo*; Shibata, Shuichi*
no journal, ,
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 Fe
O
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.
Yano, Tetsuji*; Akagi, Naoto*; Shibata, Shuichi*; Amamoto, Ippei
no journal, ,
In order to clarify the origins of the high chemical durability of iron phosphate glasses and find more stable glass composition, the transition metal oxides were added by the replacement of a part of the iron oxide, prepared the glasses by melt-quenching method and their thermal properties and chemical durabilities were measured. The structures of the glasses and their surfaces were analyzed using X-ray photoelectron spectroscopy. The bulk samples were fractured in vacuum to obtain pristine surfaces, and the photoelectrons emitted from the analyzed surface by the monochromatic X-ray irradiation were collected. From the result, the dissolution rates of the sample glasses were correlated with the structural factors obtained from the XPS data, and strong correlations with the chemical shifts of the core electron spectra of oxygen and phosphorus ions were found, which are on the different trends found in general phosphate glass system like alkali phosphate glass.
Yano, Tetsuji*; Akagi, Naoto*; Shibata, Shuichi*; Okita, Takeshi*; Matsuyama, Kanae*; Miyamoto, Shinya*; Amamoto, Ippei; Kofuji, Hirohide
no journal, ,
Surface structures of iron phosphate glasses (IPG) are investigated in order to know the origin of the high chemical durability using X-ray photoelectron spectroscopy. In this study, several IPG samples in which a part of iron oxide are replaced by other transition metal oxides are prepared and subjected to the chemical durability test. Surface structures are investigated before and after the durability test and the information on the structural changes are obtained.