STRUCTURAL STUDY OF Fe2O3-Bi2O3 GLASS SYSTEM

Dorina Rusu and I.Ardelean

 Faculty of Physics, Babes-Bolyai University, 400084  Cluj - Napoca

During recent years, there has been increasing interest in the synthesis, structure, and physical properties of heavy metal oxide glasses containing Bi2O3, due to their high refractive index, high IR transparency and high third order non-linear optical susceptibility [1,2]. 
	The structural properties of xFe2O3·(100-x)Bi2O3 glass system, with 0.5 ≤ x ≤ 50 mol% Fe2O3, were studied by EPR, X-Ray diffraction, IR and Raman spectra.
 The EPR spectra are modified with the increasing of iron content. The measurements indicate the presence of two absorption lines, one at g ≈ 4.3 for x  20 mol% Fe2O3 and another at g ≈ 2 for 20  x  50 mol% characteristic to Fe3+ ions. Furthermore, the X-Ray diffraction patters for the samples with the highest concentration of  Fe2O3 (x ≥ 35 mol%) show the presence of a Bi(FeO3) crystalline phase. 
The Raman spectra show vibrational behavior only at low wavenumbers. The bands obtained are dependent of Fe2O3 content. The bands that are evidenced from IR spectra can be assigned to the stretching mode of Bi-O bonds of strongly distorted BiO6 and to the vibrations of FeO6 group. 
These measurements indicate the structural changing in xFe2O3·(100-x)Bi2O3 glass system with the increasing of iron content.

References:
[1]. D. Hall, N. Newhause, N. Borrelli, W. Dumbaugh and D. Weidman, J. Appl. Phys. Lett.54 (1998) 1293.
[2]. T. Komatsu and K. Matusita, Thermochim. Acta 174 (1991) 131.