Aluminum Incorporation in TiO2 Rutile at High Pressure: An XRD and High-Resolution Al-27 NMR Study

作者：Escudero Alberto^*; Delevoye Laurent; Langenhorst Falko

来源：Journal of Physical Chemistry C, 2011, 115(24): 12196-12201.

DOI：10.1021/jp202930r

Aluminum incorporation into rutile (TiO2) at high pressure and hi h temperature has been studied by XRD as well as high-resolution Al-27 MAS NMR and MQ MAS NMR. High pressure enhances the Al solubility into TiO2 rutile, which is able to incorporate up to at least 5 wt % Al2O3 at 5.5 GPa. Up to four aluminum environments in octahedral coordination in ruffle have been observed. The main mechanism of solubility at low pressure is the substitution of Ti4+ by Al3+ on normal octahedral sites, but aluminum also occupies octahedral interstices of rutile, especially at higher pressures. The assignation of the NMR signals corresponding to interstitial Al and subtitutional Al associated with an interstitial Al in the rutile structure has been carried out from the combination of both XRD and NMR data and the relative higher importance of both environments at high pressure. The increase of the population of interstitial octahedral aluminum with increasing pressure gives rise to the reduction of symmetry in rutile from tetragonal to orthorhombic.

• 出版日期2011-6-23