Structural and magneto-optical properties of ferric oxide quantum dots embedded phosphate glass

In this study, phosphate glasses embedded with Fe2O3 quantum dots were prepared via a conventional melt quenching technology with further heat treatment. The effect of Fe2O3 content on the structural, optical and magneto-optical properties was investigated. The results showed that the addition of Fe2O3 had no obvious influence on the structure units that built up the host glass and the amorphous nature of glass. In the glass matrix, the existence of Fe2O3 quantum dots was confirmed by high resolution transmission electron microscope. Meanwhile, optical study clearly demonstrated a red shift in optical cut-off wavelength resulted from the size quantization effect. The highest Verdet constant (22.33°/T-cm) was measured for the glass containing 1 mol% Fe2O3, which was ~ 7 times higher than that of the glass matrix. As the increment of Fe2O3 contents, a phase evolution of Fe2O3 quantum dots from amorphous phase to γ-Fe2O3 phase was recorded due to the Ostwald Ripening effect. Interestingly, a concentration quenching phenomenon in Verdet constant was observed along with the phase evolution of Fe2O3 quantum dots. When the content of Fe2O3 is up to 2 mol%, the glass exhibited paramagnetism with the Verdet constant of − 2.833°/T-cm. This finding can provide a new idea for the development of quantum dot embedded magneto-optical glass.