Large-Scale Synthesis, Characterization, and Microwave Absorption Properties of Manganese Oxide Nanowires

Abstract

Manganese oxide nanowires have been prepared through the thermal decomposition of manganese oxalate hydrate precursor. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA) and high-resolution transmission electron microscopy (HRTEM). The microwave absorption property of the manganese oxide nanowires was measured by vector network analysis (VNA). The excellent microwave absorption property of manganese oxide nanowires was achieved due to the relatively high dielectric loss tangent. The RL value for Mn₂O₃ nanowires less than −10 dB is obtained in the 5.0–18 GHz with absorber thickness of 2.0–5.0 mm. The minimum RL value is −21.0 dB. For Mn₃O₄ nanowires, the RL value less than −10 dB is obtained in the 7.8–18.0 GHz with absorber thickness of 2.5–5.0 mm. The minimum RL value is −21.2 dB at 7.7 GHz (H band). The effective absorption bandwidth exceeding −10 dB reaches 4.4 GHz (from 6.0 to 10.4 GHz). A possible mechanism for the improvement in microwave absorption properties of manganese oxide nanowires was discussed.

Keywords:

• Nanowires
• manganese oxide
• thermal decompostion
• microwave absorption