Structural, optical and magnetic properties of Fe3O4 sputtered TeO2–PbO–B2O3 and PbO–Bi2O3–B2O3 glasses for sensing applications

The Fe3O4 nanoparticles, incorporated into two diamagnetic glasses (TeO2–PbO–B2O3 and PbO–Bi2O3–B2O3) by DC magnetron sputtering, were annealed at 300 °C for 22 h in order to investigate the influence to the thermal stability and magneto-optical properties of glasses. The structure, morphology and magnetic properties of two sputtered glasseswere compared and characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), andUV–VIS spectrameasurements. The Verdet constant of glasseswasmeasured by a home-made optical bench. Sputtered samples (Fe3O4 target)were comparedwith the one obtained by melt-quenching Fe3O4 nanoparticles. The influence of sputtered Fe3O4 layer thickness on thermal and magneto-optical performance was investigated. The results prove that the magnetic property of both glasses, and especially the TeO2–PbO–B2O3 one, is enhanced after the incorporation of 1–5 μm-thick-Fe3O4 layer deposited by sputtering. Compared with the uncoated glasses, no significant degradation in FT-IR transmittance, UV–VIS absorption and thermal stability were discovered. The TeO2–PbO–B2O3–Fe3O4 system exhibits the best thermal and magneto-optical performances for magneto optical applications, within the two glass families.