Influence of particle size on the magneto-refractive effect in PbS quantum dots-doped liquid core fiber

Abstract

In this study, magneto-refractive effects of PbS quantum dots (QDs)-doped liquid core fiber with different particle sizes were investigated. Based on the density function theory, the defect structures of PbS nanoclusters were constructed and the spin magnetic moments of sulfur (S) and plumbum (Pb) were analyzed. It indicates that the magnetic moments are mainly induced by the spin interaction between Pb 6s, 6p, and S 3p states, and the spin magnetism shows a weakening trend as the particle size increases. Based on the analysis, we experimentally studied the magneto-refractive effect with different sizes PbS QDs in liquid core fibers through a magneto-refractive index measuring system. The experimental results show that the magneto-refractive effect is strong as the size of PbS QDs decreases when the concentration is 8 mg/mL, exhibiting a maximum magneto-refractive sensitivity of -1.668×10−3 RIU/mT under the magnetic field of 0-7.89 mT, which can be used for magnetic field sensing applications.