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Rietveld refinement for Li2Si2O5 doped with vanadium

Wojciech Paszkowicz 1Suzan Abd El All 1,2Fathi M. Ezz-Eldin 2Krzysztof Kaczorek 3Ryszard Diduszko 1,3

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Center of Research and Radiation Technology, Nasr City, Cairo 0002, Egypt
3. Tele and Radio Research Institute, Ratuszowa 11, Warsaw 03-450, Poland

Abstract

Lithium-based conducting glasses are promising candidates for electrolyte materials of thin-film batteries because they exhibits isotropic ionic conductivity. However, at room temperature most of such conducting glasses exhibit relatively low ionic conductivity values, in the range 10-7 to 10-8 S/m. In order to increase the conductivity, some specific additives have been used., one of them being vanadium. In a recent work on borate glasses, vanadium dopant at a level of several percent was used for this purpose [1-3]. It has been noticed that annealing of vanadium doped borate glass results in a change of physical properties [1]. This may suggest that vanadium enters specific crystallographic sites. In this work, a related material, vanadium-doped lithium silicate glass is studied. The glass was prepared by heating a mixture of quartz (SiO2), lithium carbonate (Li2CO3) and vanadium pentoxide (V2O5) at a level of up to 5.5 weight percent at 1400 for 3 h and then cooled. As prepared glass was annealed for four hours at 550°C. This procedure gives virtually pure Li2Si2O5 phase of orthorhombic Ccc2 space group [4] with vanadium present in the lattice and traces of impuity phases. The lattice parameters are found to vary isotropically with increasing vanadium content. We notice that the observed crystallisation is faster than that reported in literature for phosphate glasses [5].

References 

[1] N.A. El-Alaily, R.M. Mohamed, Effect of irradiation on differenial thermal properties and crystallization behavior of some lithium borate glasses, Nucl. Instrum. Meth. Phys. Res. B 179 (2001) 230-242

[2] Y.-I. Lee, J.-H. Lee, S.-H. Hong, Y. Park, Li-ion conductivity in Li2O–B2O3–V2O5 glass system, Solid State Ionics 175 (2004) 687–690

[3] S.Y. Marzouk, N.A. Elalaily, F.M. Ezz-Eldin, W.M. Abd-Allah, Optical absorption of gamma-irradiated lithium-borate glasses doped with different transition metal oxides, Physica B 382 (2006) 340–351

[4] B.H.W.S. de Jong, H.T.J. Supér, A.L. Spek, N. Veldman, G. Nachtegaal, J.C. Fischer, Mixed alkali systems: Structure and 29Si MASNMR of  Li2Si2O5 and K2Si2O5, Acta Cryst. B 54 (1998) 568-577 

[5] Y. Iqbal, W.E. Lee, D. Holland, P.F. James, Crystal nucleation in P2O5-doped lithium disilicate glasses, J. Mater. Sci. 34 (1999) 4399–4411

 

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Related papers

Presentation: Poster at 11th European Powder Diffraction Conference, Poster session, by Wojciech Paszkowicz
See On-line Journal of 11th European Powder Diffraction Conference

Submitted: 2008-07-25 20:09
Revised:   2009-06-07 00:48