Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hayakawa, Kosetsu; Masebo, Yumeno*; Muraguchi, Masakazu*; Kojima, Yoichiro*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Honda, Mitsunori
no journal, ,
Soil clay minerals are expected to be a new thermoelectric material in the high temperature range, but the mechanism of their thermoelectricity has not been clarified yet. We have focused on weathered biotite (WB), a soil clay mineral composed of elements such as Si, Fe, Al, Mg, and K. We have found that the structure of WB changes under high temperature conditions, which can be observed by infrared absorption spectroscopy. In-situ observation by infrared absorption spectroscopy has shown that the structure of WB changes under high temperature conditions. However, the detailed structure has not yet been identified. In this study, we developed a method for synchrotron XAFS analysis of WB at high temperatures, where thermoelectric properties are observed, and succeeded in obtaining data from room temperature up to 873K.
intercalation into weathered biotiteMasebo, Yumeno*; Hayakawa, Kosetsu*; Muraguchi, Masakazu*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Honda, Mitsunori
no journal, ,
Natural minerals are expected as new thermoelectric materials, among which we focus on weathered biotite (WB), a kind of layered silicate mineral. WB consists of tetrahedral and octahedral sheets overlapping each other in layers, with interlayers between them. The interlayer contains K and other substances. However, the effect of the amount and type of interlayer material adsorbed on the structure has not yet been clarified. It has been known that Cs can intercalate into the interlayer of WB, but the amount of adsorption into the interlayer has not been fully investigated. In this study, we investigated the relationship between the amount of Cs adsorption and structure when Cs was intercalated into WB, and obtained Cs adsorption amounts of 0.9%, 1.7%, 3.8%, and 4.8%. XRD analysis showed that the interlayer distance increased from 9.84
, 9.91, 9.90 to 9.92 as the adsorption amount increased.
Hayakawa, Kosetsu*; Masebo, Yumeno*; Muraguchi, Masakazu*; Kojima, Yoichiro*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Honda, Mitsunori
no journal, ,
We have been studying the development of functional materials derived from WB as an application of molten-salt treatment technology. We have experimentally demonstrated that Sr can be adsorbed on the interlayer of WB by molten-salt treatment. However, the correlation between Cs adsorption and Sr adsorption has not yet been clarified, although Sr adsorption was examined for Cs adsorbed WB in a previous study. Therefore, in this study, the amount and structure of Sr adsorption with and without Cs adsorption were investigated using XRF, XRD and XAFS. The results showed that the Sr adsorption dependence may differ depending on the presence or absence of Cs in WB.