AI Article Synopsis
- A transformation from a zircon-type crystal structure to an amorphous form occurs in YVO4:Eu(3+) nanoboxes when subjected to high pressures above 12.7 GPa, as indicated by x-ray diffraction.
- The local structure of the amorphous phase resembles a scheelite-type structure rather than being entirely random.
- This phase transition is further validated by Raman spectroscopy and Eu(3+) photoluminescence data, which suggest multiple local environments for Eu(3+) in the low-pressure phase, indicating a complex structural behavior in the nanoboxes.
Article Abstract
A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu(3+) nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4. These results are confirmed both by Raman spectroscopy and Eu(3+) photoluminescence which detect the phase transition to a scheelite-type structure at 10.1 and 9.1 GPa, respectively. The irreversibility of the phase transition is observed with the three techniques after a maximum pressure in the upstroke of around 20 GPa. The existence of two (5)D0-->(7)F0 photoluminescence peaks confirms the existence of two local environments for Eu(3+), at least for the low-pressure phase. One environment is the expected for substituting Y(3+) and the other is likely a disordered environment possibly found at the surface of the nanoboxes.
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| http://dx.doi.org/10.1088/0957-4484/27/2/025701 | DOI Listing |
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