Effect of ZnO nanoparticles on structure and magnetic properties of Bi2O3-B2O3: Cr2O3 glasses

Three glass samples are synthesized by traditional melt-quenching method. The composition of the samples and their labeling is as follows: 29Bi2O3–70B2O3–1Cr2O3 (BBCZ1), 29Bi2O3–70B2O3–0.5Cr2O3–0.5ZnO (BBCZ2) and 29Bi2O3–70B2O3–1ZnO (BBCZ3). The X-ray diffraction spectra of the samples have displayed two halos at small glancing angles of 2θ (≈27o and 45°), due to absence of long-range periodic network. The significant bands have been observed in FTIR spectra of the samples attributed to [BO3] units at about 1360 cm−1 and 1210 cm−1; [BO4] units at about 1010 cm−1; and bending vibrations of OBO linkages at 635 cm−1. The semi glass forming units of [BiO6] units are identified at about 490 cm−1. The weak vibrations of ZnO bond of [ZnO4] units and/or (CrOCr) chains have been noticed at around 430 cm−1. The bands at 2970 cm−1, 2080 cm−1, 1950 cm−1 and 1740 cm−1 are observed in the spectra, which can be attributed to presence of moisture (H2O) in the glasses. The EPR spectra of the samples BBCZ1 and BBCZ2 have shown two resonance signals one at g ≈ 4.7 in low field and another at g ≈ 1.98 in high field. These resonance signals arise because of paramagnetic Cr3+ ions in the glasses. The structure and magnetic properties of three samples developed have been investigated by changing the concentrations of Cr2O3 and ZnO. Accordingly, these glasses would catch hold of possible applications as optical elements, moisture sensors and magnetic sensors etc.