Structural and physical characteristics of CeO2–GeO2–PbO glasses and glass ceramics

Samples of the xCeO2(100 − x)[GeO2·PbO] system with 0 ≤ x ≤ 15 mol% were prepared and characterized by X-ray diffraction, FT-IR spectroscopy and magnetic measurements. The X-ray diffraction (XRD) investigation revealed the presence of a crystalline phase for samples with x ≥ 3 mol%, namely that of Ce1.88Pb2.12O6.53. The structural role of germanium, lead and cerium ions was discussed. The presence of the CeO4, GeO4, GeO6 and PbO4 structural units was evidenced by FT-IR spectrocopy in the studied glasses and glass ceramics. It was shown that the ratio of the mentioned structural units depends on the CeO2 content of the xCeO2(100 − x)[GeO2·PbO] system. As a part of an on-going investigation of the physical properties of xCeO2(100 − x)[GeO2·PbO] glass ceramics, the magnetic behavior of this system was studied. The fractions of the cerium ions in the 3+ and 4+ valence states were determined.