R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2-08] Structural change of vivianite induced by dehydration and oxidization

*Ryo Yamane¹, Toru Kawamata¹, Kazumasa Sugiyama¹, Eriko Ohshima² (1. IMR, 2. NIT, Ichinoseki college)

Keywords:vivianite, dehydration, oxidization

Vivianite (Fe₃(PO₄)₂・8H₂O) exhibits structural change to santabarbarite (Fe₃(PO₄)₂OH₃・5H₂O) showing no Bragg peaks along with dehydration and oxidation of Fe. We conducted structural analysis of this change using single crystal X-ray diffraction and powder anomalous X-ray diffraction. Based on our results, arrangement of sheet structure of vivianite is firstly disturbed and then, structural change is also caused in-plain because of oxidation of Fe.