EPR and FT-IR spectroscopic studies of Bi2O3–B2O3–CuO glasses

doi:10.1016/j.physb.2008.06.016

Physica B: Condensed Matter

Volume 403, Issues 19–20, 1 October 2008, Pages 3682-3685

https://doi.org/10.1016/j.physb.2008.06.016 Get rights and content

Abstract

EPR and FT-IR absorption measurements have been performed for xCuO·(100−x)[2Bi₂O₃·B₂O₃] glass system, with 0⩽x⩽50 mol%. The mode in which the addition of the copper ions influences the structure of 2Bi₂O₃·B₂O₃ glass matrix was analyzed. The EPR absorption spectra revealed the presence in the glass structure of Cu²⁺ ions in axially distorted octahedral environments. EPR data pointed out the simultaneous presence of Cu²⁺ and Cu⁺ ionic species in the glasses with x⩾5 mol%. For x>10 mol%, the Cu²⁺ ions participate in the superexchange magnetic interactions, which increase with CuO content. The FT-IR spectra showed the presence of some bands that are assigned to vibrations of Bi–O bonds from BiO₃ pyramidal and BiO₆ octahedral units and B–O bonds from BO₃ and BO₄ units.

The data obtained by these measurements reveal the structural changes in the 2Bi₂O₃·B₂O₃ glass matrix by controlled doping of CuO.

Introduction

Both Bi₂O₃ and B₂O₃ oxides are known as network formers but Bi₂O₃ is an unconventional one. The physical properties of Bi₂O₃-based glasses are characterized by high refractive index, excellent infrared transmissions, high nonlinear optical susceptibility, and high polarizability [1], [2], [3], [4]. In Bi₂O₃-based glasses the bismuth ions may appear in BiO₃ pyramidal and BiO₆ octahedral units [2], [3], [4].

The borate glasses, in particular, have been the subject of numerous studies due to their structural peculiarities [5], [6], [7]. The structure of Bi₂O₃–B₂O₃ glass system was studied through IR absorption [3], Raman scattering [8], NMR, and EPR [8], [9] spectroscopies. Adding copper ions in the content of oxide glasses made it very interesting due to their electrical and magnetical properties [10].

In this research we present the experimental data obtained by EPR and FT-IR spectroscopies for xCuO·(100−x)[2Bi₂O₃·B₂O₃] glass system, with 0⩽x⩽50 mol%.

Section snippets

Experimental

Glass samples belonging to xCuO·(100−x)[2Bi₂O₃·B₂O₃] system were prepared using reagent grade purity H₃BO₃, Bi(NO₃)₃^⋅5H₂O, and CuO in suitable proportion to obtain the desired compositions. According to the above formula, the components were mixed and introduced directly in an electric furnace at 1250 °C for 5 min. Sintered corundum crucibles were used. The structure of the samples was studied by means of X-ray diffraction and no crystalline phase was detected up to 50 mol% CuO.

The EPR spectra

EPR data

The EPR spectra of the xCuO·(100−x)[2Bi₂O₃·B₂O₃] are shown in Fig. 1. According to Fig. 1 the obtained absorption spectra are asymmetric, characteristic for Cu²⁺ (3d⁹) ions in axially distorted octahedral symmetric sites. For samples with low concentration range, 1⩽x⩽5 mol%, the EPR spectra show hyperfine structure (hfs) due to the interactions of the unpaired electron spin with the nuclear one (I=3/2), characteristic to Cu²⁺ ions. The hfs is resolved in the parallel band of the EPR spectra. The

Conclusion

Homogeneous glasses of xCuO·(100−x)[2Bi₂O₃·B₂O₃] system were obtained for 0⩽x⩽50 mol%. For all samples, the EPR absorption spectra are due to Cu²⁺ ions. EPR data suggest that for x⩽10 mol% the copper ions are isolated or/and participate in the dipole–dipole interaction and for higher concentrations they experience superexchange magnetic interaction. The J does not depend linearly on x, suggesting that for x⩾5 mol% the Cu⁺ ions are present in the studied glasses but they do not contribute to the

References (21)

R.A. Condrate
J. Non-Cryst. Solids
(1986)
V. Dimitrov et al.
J. Non–Cryst. Solids
(1994)
R. Iordanova et al.
J. Non-Cryst. Solids
(1996)
W.H. Dumbaugh et al.
J. Am. Ceram. Soc.
(1992)
S. Hazra et al.
Phys. Rev. B
(1995)
Y. Dimitriev et al.
J. Sci. Lett.
(1990)
S. Hazra et al.
Phys. Rev. B
(1997)
J. Wang et al.
Glass Structure by Spectroscopy
(1976)
E.I. Kamitsos et al.
Phys. Chem. Glasses
(1989)
E.I. Kamitsos et al.
J. Phys. Chem.
(1987)

There are more references available in the full text version of this article.

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EPR and FT-IR spectroscopic studies of Bi2O3–B2O3–CuO glasses

Abstract

Introduction

Section snippets

Experimental

EPR data

Conclusion

J. Non-Cryst. Solids

J. Non–Cryst. Solids

J. Non-Cryst. Solids

J. Am. Ceram. Soc.

Phys. Rev. B

J. Sci. Lett.

Phys. Rev. B

Glass Structure by Spectroscopy

Phys. Chem. Glasses

J. Phys. Chem.

EPR and FT-IR spectroscopic studies of Bi₂O₃–B₂O₃–CuO glasses