Structural Modification of Weathered Biotite Induced by Cs Intercalation

This study aimed to elucidate the effects of Cs adsorption on the structure and physical properties of weathered biotite (WB) using a molten salt method. WB samples with adsorbed Cs were prepared by varying the amount of added CsCl through the molten salt method. The samples were analyzed using X-ray fluorescence, X-ray diffraction, and X-ray absorption fine structure (XAFS). The results showed that the amount of Cs adsorbed increased in proportion to the amount of CsCl added, while the interlayer spacing remained nearly constant, confirming that the layered structure of WB was preserved. Furthermore, XAFS analysis of Si, a major component of WB’s framework, revealed changes in the electronic structure around Si due to Cs adsorption. These findings indicate that Cs adsorption alters the electronic structure of Si in WB, suggesting the potential for developing novel materials based on the unique properties of WB.