Preliminary results of 57Fe Mössbauer spectroscopy of metamict samarskite after one-hour high temperature annealing in argon

The preliminary results of 57Fe Mössbauer spectroscopy and X-ray diffraction (XRD) of fully metamict samarskite dated at ~1500 Ma, which absorbed α-dose of 6.5 × 1017 α-decay mg-1, are reported after one-hour annealing at 673, 873, 1173 and 1373 K in argon atmosphere. Metamict minerals contain radioactive elements that degrade their crystal structures over geological time. All the Mössbauer spectra obtained can be fitted to two quadrupole doublets assigned to Fe2+ and Fe3+ in octahedral positions. The relative contribution of Fe2+ (Fe2+/Fe) reaches a minimum of 0.10 at 1173 K.

High Temperature Study of Metamict Rinkite

Metamict minerals contain radioactive elements that degrade their crystal structure. During the annealing process under ambient pressure in argon atmosphere the sample of metamict rinkite recrystallizes to the primary crystalline form at 700°C. Further heating leads to the formation of a new crystalline phase.

High Temperature Study of Metamict Steenstrupine

Metamict minerals contain radioactive elements that degrade their crystal structure. Unlike other metamict minerals, annealing process under ambient pressure do not lead to direct recrystallization of steenstrupine.