Synchrotron radiation investigations of the Sr2MgSi2O7:Eu2+,R3+ persistent luminescence materials
来源期刊：JOURNAL OF RARE EARTHS2009年第4期
论文作者：Pavel Novák Jukka Hassinen Mika Lastusaari Maria Malkam Janne Niittykoski Jorma Hd Taneli Laamanen Tuomas Aitasalo
Key words：strontium magnesium disilieate; europium; persistent luminescence; synchrotron radiation; thermoluminescence; mechanism; rare earths;
Abstract: The electronic and defect energy level structure of polycrystalline Sr2MgSi2O7:Eu2+,R3+ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies (UV-VUV emission and excitation,X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS)).Special attention was paid on the effect of the R3+ co-dopants on the persistent luminescence properties of the materials.Theoretical calculations using the density functional theory (DFT) were carried out simultaneously with the experimental work.The experimental band gap energy (Eg) value of ca.7.1 eV agreed very well with the DFT value of 6.7 eV.The variation of the Eg value was attempted to relate with the trap structure as well as with the different properties of the R3+ co-dopants.The trap level energy distribution depended strongly on the R3+ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same,however.The different processes in the mechanism of persistent luminescence from Sr2MgSi2O7:Eu2+,R3+ were assembled and their contributions discussed.
Pavel Novák1，Jukka Hassinen2，Mika Lastusaari3，Maria Malkam4，Janne Niittykoski2，Jorma Hd5，Taneli Laamanen6，Tuomas Aitasalo2
(1.Institute of Physics,Academy of Sciences of the Czech Republic,CZ-16253 Prague 6,Czech Republic;
2.Department of Chemistry,University of Turku,FI-20014 Turku,Finland;
3.o;
4.a)ki(a;
5.o)ls(a)(o;
6.a)
Abstract:The electronic and defect energy level structure of polycrystalline Sr2MgSi2O7:Eu2+,R3+ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies (UV-VUV emission and excitation,X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS)).Special attention was paid on the effect of the R3+ co-dopants on the persistent luminescence properties of the materials.Theoretical calculations using the density functional theory (DFT) were carried out simultaneously with the experimental work.The experimental band gap energy (Eg) value of ca.7.1 eV agreed very well with the DFT value of 6.7 eV.The variation of the Eg value was attempted to relate with the trap structure as well as with the different properties of the R3+ co-dopants.The trap level energy distribution depended strongly on the R3+ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same,however.The different processes in the mechanism of persistent luminescence from Sr2MgSi2O7:Eu2+,R3+ were assembled and their contributions discussed.
Key words:strontium magnesium disilieate; europium; persistent luminescence; synchrotron radiation; thermoluminescence; mechanism; rare earths;
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