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

Sooraj H. Nandyala1,2*, Graham Hungerford3, S. Babu4, J. L. Rao4, Isabel B. Leonor1,2 , Ricardo Pires1,2,  Rui L. Reis1,2

1ICVS/3B's, PT Government Associated Laboratory, Braga/Guimarães, Portugal

23B's Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on TissueEngineering and Regenerative Medicine, Avepark, Barco, 4805-017, Guimarães, Portugal

3HORIBA Jobin Yvon IBH Ltd., 133 Finnieston Street, Glasgow G3 8HB, United Kingdom

4Department of Physics, Sri Venkateswara University, Tirupati 517 502, Andhra Pradesh, India

Adv. Mater. Lett., 2016, 7 (4), pp 277-281

DOI: 10.5185/amlett.2016.6243

Publication Date (Web): Mar 07, 2016

E-mail: nandyala.sooraj@gmail.com

Abstract


Gadolinium, Gd3+ (4f7), containing glasses are particularly interesting owing to their magnetic and optical properties. Gd3+ has an electron paramagnetic resonance (EPR) centre, which is often used as the EPR probe in different matrices. Another important feature of Gd3+ is that emits ultraviolet radiation (UVR) at around 310 – 313 nm from the 6P7/2 à8S7/2 transition and is suitable for the treatment of skin disease.  Here, we report on Gd3+ 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 Gd3+ ions. The stimulated emission cross sections (σPE×10−21 cm2) of the UV emission transition 6P7/2 à8S7/2 were also reported in the above three approaches. 

Keywords

Gd3+ glass, EPR studies, time resolved emission spectra, calcium phosphate material.

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