Optical processes in YVO4: Eu3+ across zircon-to-scheelite phase transition.
Résumé
The luminescence processes across zircon-to-scheelite phase transition in undoped YVO4 and Eu3+-doped YVO4 are investigated by measuring the Raman, excitation and emission spectra and decay characteristics of the compounds with respect to high hydrostatic pressure up to 200 kbar. The scheelite polymorphs obtained after releasing the high pressure show no luminescence when undoped, even down to 10 K, but when activated with Eu3+ exhibit the characteristic scheelite-related Eu3+ emission but with low intensity. This emission is produced upon UV excitation in zircon inclusions that remain after the pressure treatment.