Solid State Science and Technology, Vol. 17, No 2 (2009) 50-58

ISSN 0128-7389

Corresponding Author: shahira_alias@yahoo.com

50

 

STRUCTURAL STUDIES ON MAGNESIUM CALCIUM TELLURITE DOPED

WITH Eu2+ AND Dy3+

Nur Shahira Alias, Rosli Hussin, Musdalilah Ahmad Salim, Siti Aisyah Ahmad Fuzi,

Mutia Suhaibah Abdullah, Suhailah Abdullah and Mohd Nor Md Yusof.

Phosphor Research Group, Jabatan Fizik, Fakulti Sains,

Universiti Teknologi Malaysia, 81310 Skudai, Johor.

 

ABSTRACT

The samples of phosphor material based on alkali earth tellurite, doped with rare earth have been prepared using solid state reaction method. The samples are with the composition in mol %: xMgO-(30-x)CaO-70TeO2 with 0≤x≤30 mol%, and have beendoped with Eu2O3(2mol%) and Dy2O3(1mol%). The structure of the samples have beeninvestigated by means of X-Ray Diffraction, Raman and Infrared spectroscopy. The xray diffraction results show that two phase are observed in the samples, which is MgTe2O5 and CaTe2O5 phase. Raman spectroscopy studies show that the vibrations of the samples are identical with the α-TeO2 vibrations, with a shift about 40-50cm-1. Strong bands are observed located at around 435, 616, 689, 785, and 807cm-1. As the concentration of the modifier, MgO and CaO increased, the coordination of TeO4 are transform from the corner sharing, α-TeO2 structure to the edge sharing, β-TeO2 structure. It is also indicated that the increasing of MgO contribute to the increasing of symmetry vibration of TeO4 molecule, υs(TeO4), while the addition of CaO increased the asymmetry vibration of TeO4 molecule, υas(TeO4). The comparison between Ramanand IR spectra is also include to identify the mode vibration of the samples.

 

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