Figure 6.

In situ polarized FTIR spectra of a single crystal of MFM-300(Ga₂) in the ν(OH) and CO₂ combination band region, (a) under 1 bar He and (b) under 1 bar of CO₂ (the contribution from gaseous CO₂ has been subtracted), recorded at two orthogonal polarizations P1 (red) and P2 (blue), each aligned with a crystal edge. Arrows indicate the direction of changes on rotating polarization from P1 to P2. The face index of the single crystal which was used for this study is shown in (c). P2 is along the c-axis, and P1 is along the ab plane.