Cesium Oxo-fluoro-aluminates in the CsF-Al 2 O 3 System: Synthesis and Structural Characterization.

In an experiment combining various approaches, a precise examination of a portion of the phase diagram of a CsF-Al 2 O 3 system was carried out up to 40 mol% Al 2 O 3 . CsF-Al 2 O 3 solidified mixtures have been investigated using high-field solid-state NMR ( 133 Cs, 27 Al, and 19 F) spectroscopy and X-ray powder diffraction over a broad range of compositions with synchrotron powder diffraction and Rietveld analysis. A new cesium oxo-fluoro-aluminate, Cs 2 Al 2 O 3 F 2 , was discovered, prepared, and structurally analyzed by synchrotron diffraction analysis. In addition to Cs 2 Al 2 O 3 F 2 , we have synthesized the following pure compounds in order to aid in the interpretation of NMR spectra of the solidified samples: CsAlF 4 , Cs 3 AlF 6 , and CsAlO 2 .