TiN/BN composite with excellent thermal stability for efficiency microwave absorption in wide temperature spectrum

High-efficiency and temperature-insensitive microwave absorbing materials (MAMs) are ideal for high-temperature electromagnetic attenuation. Herein, the titanium nitride/boron nitride (TiN/BN) composite with TiN as the loss unit and BN as the impedance matching unit has been constructed by the in-situ synthesis method. The insulating BN not only effectively regulates and optimizes the conductivity and impedance matching of the material but also imparts steady cyclic microwave absorption properties. The steady dielectric loss ensures that TiN/BN composite has robust high-temperature absorption properties at X-band, with a minimum reflection loss (RL min ) of −16.74 dB at 873 K and an effective absorption bandwidth (EAB) of 3.26 GHz in the temperature range of 293–873 K. Compared with the TiN/SiO 2 absorbers with a single system, the TiN/BN/SiO 2 composite keeps reliable high temperature absorbing properties at 873 K. This work confirms that wave-transparent materials for dielectric property modulation can resolve poor temperature stability of effective absorption and non-reusability for high-temperature absorbing materials, providing inspirations for designing efficiency high-temperature microwave absorbers.