Effect of hydrogenation on the microwave absorption properties of BaTiO3 nanoparticles

Abstract

Microwave absorbing materials (MAMs) have numerous important applications in electronic communications, signal protection, radar dodging, etc. Although it has been proposed as a promising MAM, BaTiO₃ has a high reflection coefficient at the interface with air, causing a large reflection. Thus, its efficiency of microwave absorption is not satisfactory. Here, we report that hydrogenation has largely improved the microwave absorption of BaTiO₃ nanoparticles. Hydrogenation is performed on BaTiO₃ nanoparticles by treating pristine BaTiO₃ nanoparticles at 700 °C for 4 hours in a pure H₂ environment. The enhanced microwave absorption efficiency with a reflection loss value (−36.9 dB) is attributed to the increased resonance of polar rotations with the incident electromagnetic field which is amplified by the increased interfacial polarization caused by the built-in electrical field along the boundaries between different grains created within these nanoparticles.