Fiber optic magnetic field sensor using Co doped ZnO nanorods as cladding

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Development of sensitive and cost-effective magnetic field sensors is crucial for various applications.
• Zinc oxide (ZnO) nanostructures offer promising properties for sensor development.
• Doping ZnO with transition metals can modify its magnetic and optical characteristics.

Purpose of the Study:

• To propose and experimentally demonstrate a fiber optic magnetic field sensor.
• To investigate the effect of cobalt (Co) doping on ZnO nanorods for sensing applications.
• To evaluate the performance of the Co-doped ZnO nanorod-based sensor.

Main Methods:

• Synthesis of pristine and Co-doped ZnO nanorods (5-20 at% Co) via hydrothermal method.
• Characterization using X-ray diffraction (XRD), XPS, SEM, VSM, and optical absorption.
• Fabrication of a fiber optic sensor by coating cladding-modified fiber with Co-doped ZnO nanorods.

Main Results:

• XRD and XPS confirmed successful incorporation of Co into the ZnO lattice without structural changes.
• Co doping transformed the diamagnetic behavior of ZnO to paramagnetic.
• The sensor exhibited a maximum sensitivity of ~18% for 15 at% Co-doped ZnO nanorods within a 17-180 mT range.

Conclusions:

• Co-doped ZnO nanorods are effective sensing materials for fiber optic magnetic field sensors.
• The proposed sensor offers high sensitivity, reproducibility, low-cost fabrication, and simple sensor head preparation.
• This technology presents an attractive solution for magnetic field detection.