Structural and luminescence properties of magnesium silico-phosphate doped with europium and dysprosium ions

• Main Author: Ahmad Salim, Musdalilah
• Format: Thesis
• Language: English
• Published: 2011
• Subjects: QC Physics
• Online Access: http://eprints.utm.my/id/eprint/33414/5/MusdalilahAhmadSalimMFS2011.pdf; http://eprints.utm.my/id/eprint/33414/; http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:69578?site_name=Restricted Repository

Phosphor materials based on magnesium silico-phosphate was prepared via solid-state reaction method. The series of samples were in the form of xMgO (70-x) SiO230P2O5: yEu2O3, zDy2O3 with 0 = x = 30 mol %, 0 = y = 1 mol % and 0 = z = 4 mol %. The X-ray diffraction pattern confirms that the synthesized material consists of SiO2, SiP2O7, Mg2P4O12 and MgSiO3. FTIR spectroscopy was carried out to investigate the structure feature and vibrational study of phosphor material. The introduction of MgO yields the oxygen bridge like SiO-, PO-, Si-O-Si, P-O-P and Si-O-P linkages and was revealed that the hydroscopic properties from P2O5 can be reduced. Other than that MgO also take part in the formation of P=O:Mg by the breakdown of the vibration of double bond, P=O. The morphology and grain size of phosphor material was studied using SEM. It proves that doping material addition changes the morphology of host system. EDAX study was employed to give a clear evidence of doping material that had been used in this study. The photoluminescence characteristics originating of europium and dysprosium trivalent were also investigated. The addition of Dy3+ as co-dopant in the 20MgO-50SiO2-30P2O5: 1Eu2O3 shows the quenching effect in the emission spectra. The photoluminescence intensity of Eu3+ decrease gradually with the concentration of the co-dopant in the range from 1 mol% to 4 mol%. The significantly intense emission peak was obtained at 474 nm (blue), 563 nm (yellow), 585 nm (orange), and 610, 645, and 658 nm (red) for 20MgO-50SiO2-30P2O5: 1Eu2O3, 1Dy2O3. The energy absorbed by Dy3+ is transferred to Eu3+ and energy levels at each transition were provided. The transition of Eu3+, 5D0 ? 7F2 and Dy3+, 4F9/2 ? 6H13/2 are hypersensitive electronic dipole transition and greatly affected by the coordination environment which are located at low-symmetry local site. Experimental results revealed that the luminescence can be affected by crystal structure, doping material concentration and morphology.