Defect-induced magneto-optic properties of MgO nanoparticles realized as optical-fiber-based low-field magnetic sensor

Abstract

The spintronic applications of defect-magnetism in oxides have been explored for a long time. However, limited success has been obtained. We report on FCC-structured, magnesium oxide nanoparticles (20 nm) deposited on the mirror-surface of single-mode-optical-fiber as an effective low-field magnetic sensor. These show magnetic behavior and good magneto-optic-Kerr-effect signal. Red-shift phenomenon has been found in the birefringence pattern, when a magnetic field is applied. The sensitivity of red-shift is 202.4 pm/mT. Such red-shift phenomenon is ascribed to the influences of defect-induced magnetism on the optical-wave propagation.