Enhanced and stable high-temperature microwave absorption via the construction of a three-dimensional TiO₂ porous network structure in Sc₂Si₂O₇ ceramics

Fabricating inorganic ceramics with stable high-temperature electromagnetic (EM) attenuation properties via the construction of three-dimensional (3D) nanofiber networks continues to pose significant challenges. In this work, the dielectric properties and microwave attenuation performance were significantly enhanced through the precise morphological and architectural control of a 3D TiO₂ nanowire (TiO₂ nws) network within Sc₂Si₂O₇, which was achieved by modulating the sintering temperature during coprecipitation and sintering. The TiO₂ nws/Sc₂Si₂O₇ (ST-800, sintered at 800 ℃) exhibited excellent microwave absorption properties, with a minimum reflection loss (RL_min) of –21.45 dB at 2.25 mm and an effective absorption bandwidth (EAB) reaching 3.7 GHz at a matching thickness of 2.55 mm. The radar cross-section significantly decreased by 17.28 dB·m² at 0°. Moreover, ST-800 has a broad temperature range from 100-600 °C, with an RL below –20 dB, an EAB exceeding 3.8 GHz, and a matching thickness of less than 2.75 mm. This stable and excellent microwave absorption performance at elevated temperatures can be attributed to the well-maintained impedance matching behavior, along with the synergistic compensation between the polarization loss and conduction loss across a broad temperature range. These findings provide valuable guidance for the development of high-temperature stable EM wave absorbing materials.