Dielectric properties and structural features of barium-iron phosphate glasses

• Published in: Journal of non-crystalline solids Vol. 336; no. 3; pp. 159 - 164
• Main Authors: Bergo, P, Reis, S.T, Pontuschka, W.M, Prison, J.M, Motta, C.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2004; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mössbauer effect; other γ-ray spectroscopy; Permittivity (dielectric function); Physics; P147; D180; Moessbauer effect; Inorganic compounds; Microwave radiation; Dielectric properties; Transition element compounds; Differential thermal analysis; Infrared spectra; Phosphate glass; Valence; Barium oxides; Transition elements; Iron oxides; Permittivity
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2004.02.008

The dielectric constant of barium-iron phosphate glasses with the general composition (40− x)BaO · xFe 2O 3 · (60− x)P 2O 5 has been investigated at two fixed frequencies (100 kHz and 9.0 GHz). The dielectric constant measured using microwave technique, and the ratio O/P of these glasses increase with increasing Fe 2O 3 content. The structure and valence states of the iron ions in these glasses were investigated using Mössbauer spectroscopy, infrared spectroscopy and differential thermal analysis. Both Fe(II) and Fe(III) ions present in these glasses in octahedral coordination act as permanent dipoles, and the increase of the iron concentration increase these permanent dipoles, contributing to the dielectric constant.