Time Resolved Emission Spectra And Electron Paramagnetic Resonance Studies Of Gd3+ Doped Calcium Phosphate Glasses

Abstract

Gadolinium, Gd 3+ (4f 7), containing glasses are particularly interesting owing to their magnetic and optical properties. Gd 3+ has an electron paramagnetic resonance (EPR) centre, which is often used as the EPR probe in different matrices. Another important feature of Gd 3+ is that emits ultraviolet radiation (UVR) at around 310-313 nm from the 6 P 7/2  8 S 7/2 transition and is suitable for the treatment of skin disease. Here, we report on Gd 3+ doped calcium phosphate host glasses with four different concentrations; 0.5-4 mol % and labelled as 0.5Gd, 1Gd, 2Gd and 4Gd. A strong emission peak at 310 nm was observed in the reported glasses with excitation at 274 nm. The emission spectra can also be obtained at specific times during the decay. The time resolved emission data was analyzed with three different approaches namely, simple exponential, NED distribution and stretched exponential. The other approaches confirm the single exponential behaviour for all samples with deviation for the 0.5 Gd. The decay associated spectra (DAS) for the 0.5 Gd indicate that both decays have the same origin. The EPR spectrum exhibits several resonance signals characteristic of Gd 3+ ions. The stimulated emission cross sections (σ P E ×10 −21 cm 2) of the UV emission transition 6 P 7/2  8 S 7/2 were also reported in the above three approaches.

Structure and Luminescent Properties of Niobium-Modified ZnO-B2O3:Eu3+ Glass

“…The most intensive feature is assigned to the impurities of isolated Mn 2+ ions. The observed resonance signals in the spectral range 0–300 mT are assigned to the presence of Eu 2+ ions in a highly asymmetric site environment [ 32 , 33 ]. The EPR spectra indicate the presence of low concentrations of Eu 2+ ions in the obtained glasses, based on the comparison between the background spectrum and the analyzed spectra.…”

Network Structure and Luminescent Properties of ZnO–B2O3–Bi2O3–WO3:Eu3+ Glasses

“…6.0, 4.7, 3.4, and 2.8 located in the range 0-300 mT. These signals could be assigned to Eu 2+ ions [42,43] localized in a low-symmetry crystal field with large zero-field splitting (D > hν).…”

“…In the spectra of ZBBW5:Eu are discernable a set of not-well-resolved and low-intensive signals with g factors about 6.0, 4.7, 3.4, and 2.8 located in the range 0-300 mT. These signals could be assigned to Eu 2+ ions [42,43] localized in a low-symmetry crystal field with large zero-field splitting (D > hν).…”