Ma. Castro et al., FORMATION AT 300-DEGREES-C OF A HIGH-TEMPERATURE DISILICATE FROM HYDRATED LUTETIUM IN A LAYERED ALUMINOSILICATE, Clay Minerals, 31(4), 1996, pp. 507-512
The interaction between interlamellar Lu(III) cations and the layered
silicate structure has been studied by means of MAS-NMR, XRD and EDX.
Irreversible fixation of exchangeable Lu(III) cations upon hydrotherma
l treatment at 300 degrees C of Lu-saturated montmorillonite is report
ed, through the formation of the crystalline phase Lu2Si2O7 It is show
n that the lowest temperature previously described for this reaction,
400 degrees C, does not indicate a thermodynamic boundary. This basic
solid-state finding is relevant for some clay applications such as tho
se related to the safety of nuclear waste repositories with engineerin
g barriers.