Photoluminescence and radioluminescence study of NaMgF sub(3):Eu nanoparticles

• Published in: Radiation measurements 2014-12, Vol.71, p.258-261
• Main Authors: Gaedtke, C, Williams, GVM
• Format: Article
• Language: English
• Subjects: Activated; Decay; Defects; Distortion; Emission; Energy transfer; Nanoparticles; Photoluminescence; Radiation measurement
• ISSN: 1350-4487
• DOI: 10.1016/j.radmeas.2014.01.003

Photoluminescence (PL) and radioluminescence (RL) measurements were made on small ( similar to 25 nm) NaMgF sub(3) nanoparticles doped with Eu concentrations ranging from 0.1% to 5%. We find that they contained Eu super(3+), Eu super(2+), and an additional unidentified defect with a broad PL emission similar to 470 nm. Similar to previous measurements on larger (57 nm-77 nm) NaMgF sub(3):Eu nanoparticles with 1% Eu and 5% Eu, we find that the PL lifetime decreases with increasing Eu concentration that can be attributed to Eu energy transfer to non-radiative recombination sites. However, there is no change in the fraction of Eu super(3+) distorted sites. The similar to 470 nm PL defect peak was also reported for larger nanoparticles, which suggests that this peak arises from similar unidentified point defects. However, the activated non-radiative decay for the small nanoparticles has a significantly lower activation energy. The Eu super(3+) RL decreases by only 2.3% at 10 kGy for low Eu concentrations.