Nitrogen-doped rutile TiO₂ enhances microwave absorption performance by constructing defect dipoles

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Advanced microwave absorption materials are crucial for electromagnetic pollution control and military stealth.
• Traditional rutile titanium dioxide (TiO2) exhibits limited microwave absorption capabilities.
• Optimizing TiO2's intrinsic properties is key to improving its application potential.

Purpose of the Study:

• To prepare nitrogen (N)-doped TiO2 with controllable point defects.
• To investigate the effect of N doping on the dielectric properties and microwave absorption of TiO2.
• To explore point defect engineering for enhancing TiO2's microwave absorption performance.

Main Methods:

• Sol-gel method for synthesizing N-doped TiO2.
• Microwave absorption performance evaluation.
• Electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) for material characterization.

Main Results:

• N-doping effectively regulated the complex dielectric constant and microwave absorption.
• A minimum reflection loss (RLmin) of -37.5 dB and an effective absorption bandwidth (EAB) of 3.4 GHz were achieved at a 2.0 mm thickness with an N/Ti molar ratio of 1.7.
• N-doping induced oxygen vacancies and composite defects, enhancing defect dipole polarization.

Conclusions:

• Point defect engineering via N-doping offers a novel strategy to enhance rutile TiO2's microwave absorption performance.
• The study provides a pathway for optimizing TiO2-based materials for electromagnetic applications.
• This research expands the potential applications of TiO2 in microwave absorption fields.