Pressure-induced amorphization in Eu(OH) 3: A luminescence study
Abstract
The phase behavior of europium hydroxide was investigated as a function of pressure by monitoring the luminescence from the Eu 3+ ion. The spectra suggested that crystalline, UCl 3-type Eu(OH) 3 transforms to amorphous Eu(OH) 3 at high pressure. This transition started at about 3 GPa at room temperature. The pressure-induced amorphous Eu(OH) 3 reverted back to the original, crystalline, UCl 3-type structure when the pressure was released. Analysis of the Eu 3+ ion's luminescence spectrum from the amorphous state of Eu(OH) 3 indicated that the site symmetry of the Eu 3+ ion is much lower and that its coordination number does not change significantly from those in crystalline Eu(OH) 3. The luminescence spectrum from the amorphous phase in the region from about 15700 to 20000 cm -1 suggests the presence of some Eu 2+ ion, which could indicate that the pressure-induced amorphization is accompanied by a partial reduction of the Eu 3+ ion.
- Publication:
-
Solid State Communications
- Pub Date:
- March 1994
- DOI:
- 10.1016/0038-1098(94)90503-7
- Bibcode:
- 1994SSCom..89.1005C