Hydrogen Sensing of Heterostructured Magnetic Nanospheres With Different Fe to Zn Molar Ratio

This article describes the fabrication of Zinc Ferrite-Zinc oxide (ZFO-ZnO) heterostructure devices and the various sensing schemes that can be exploited using the same. A solvothermal approach has been used for the synthesis of ZFO-ZnO heterostructures having different compositions. The investigation of magnetic and electric properties is performed by varying the ratio of Zn
$^{2+}$
and Fe
$^{3+}$
ions. These heterostructures show enhanced magnetization with (i) an increase in the concentration of Fe
$^{3+}$
ions and (ii) exposure to hydrogen (H
$_2$
) gas. These fine molar ratio adjustments in magnetism are engineered to obtain desirable sensing properties. We fabricated several two-terminal devices for the study of multiple sensing schemes. These devices demonstrated a linear current-voltage characteristic, with enhanced electrical resistance when the Fe
$^{3+}$
ion concentration is reduced. Keywords- Magnetic analysis, Zinc Ferrite-Zinc oxide, sensors, room temperature, heterostructures, tunability and nanotechnology