Solid solutions with the whitlockite structure Ca9Gd1 –хEux(PO4)7 and Ca8MgGd1 –хEux(PO4)7 were synthesized by standart tecnique. The compounds have been characterized using various methods, including X-ray diffraction, second harmonic generation,… Click to show full abstract
Solid solutions with the whitlockite structure Ca9Gd1 –хEux(PO4)7 and Ca8MgGd1 –хEux(PO4)7 were synthesized by standart tecnique. The compounds have been characterized using various methods, including X-ray diffraction, second harmonic generation, and luminescence spectroscopy. The optical characteristics, excited-state lifetimes, and quantum yield were studieid. Under excitation at 395 nm, the compounds exhibit bright luminescence in the orange-red spectral region. The concentration of Eu3+ cation were optimized for obtaining the most efficient luminescence in the red spectral region: x = 0.75 for Ca8MgGd1 –хEux(PO4)7 and x = 1 for Ca9Gd1 –хEux(PO4)7. Efficient Gd3+ → Eu3+ energy transfer has been demonstrated, with an increase in photoluminescence intensity by a factor of 2.5. The quantum yield in the solid solutions reaches 49.5%, which is twice that in a commercially available Y2O3:Eu3+-based phosphor.