Structural Refinement and Optical Properties of Strontiowhitlockite-Based Mixed Phosphate-Vanadates

Area of Science:

• Materials Science
• Solid-State Chemistry
• Luminescence

Background:

• Strontium-based whitlockites (Sr-WHT) are known for their potential applications.
• Doping with rare-earth ions like Europium (Eu3+) can impart luminescence properties.

Purpose of the Study:

• To synthesize novel strontium-based whitlockites doped with Eu3+ ions.
• To investigate the formation of anion mixed salts within the Sr-WHT structure.
• To characterize the photoluminescence properties of these new materials for potential applications.

Main Methods:

• High-temperature solid-state synthesis in air.
• Rietveld refinement for structural analysis.
• Infrared (IR) and Raman spectroscopy for structural confirmation.
• Photoluminescence (PL) spectroscopy and luminescence decay measurements.

Main Results:

• Successful synthesis of Sr-based whitlockites doped with Eu3+ ions.
• First-time demonstration of anion mixed salts, Sr8ZnEu(PO4)7-x(VO4)x, with a Sr-WHT structure.
• Establishment of a continuous solid solution series for 0 ≤ x ≤ 6.
• Observation of stable red photoluminescence attributed to Eu3+ 4f-4f transitions.
• Calculation of color coordinates for single-phase mixed salts.

Conclusions:

• The synthesized mixed phosphate-vanadate salts represent a novel class of phosphors.
• These materials exhibit stable red luminescence, suitable for w-LED applications.
• The structural and luminescence properties indicate their potential as red-emitting components in w-LEDs.