Synthesis by Coprecipitation of Al-Substituted Hydroxysulphate Green Rust Fe_4~ⅡFe_(2-y)~ⅢAl_y~Ⅲ(OH)_(12)SO_4, nH_2O

摘要

Al-substituted hydroxysulphate green rust (Al-GR{SO_4}) were synthesised by the co-precipitation of Fe~Ⅱ, Fe~Ⅲ and Al~Ⅲ cations. The Al-GR{SO_4} crystals (～50 nm) are significantly smaller than the hydroxysulphate green rust GR{SO_4} crystals (～500 nm). The Moessbauer spectrum of Al-GR{SO_4} was adjusted with two ferrous doublets D_1 and D_3 and one ferric doublet D_2. Doublet D_3 is attributed to Fe~Ⅱ ions that have Al~Ⅲ ions as a first neighbour.