Rational Design of a Core–Shelled Ti3AlC2@La2Zr2O7 Composite for High-Temperature Broadband Microwave Absorption

Microwave-absorbing materials adapting to high temperatures and harsh environments are in great demand. Herein, a core-shelled Ti3AlC2@La2Zr2O7 (TAC@LZO) composite was designed and fabricated by encapsulating the La2Zr2O7 (LZO) thermal insulation ceramic on the surface of highly conductive Ti3AlC2 (TAC) via chemical coprecipitation and subsequent heat treatment. The continuous LZO ceramic coating on the surface improved the oxidation resistance of the composite at 600 °C and modulated its dielectric properties. The TAC@LZO composite exhibited an excellent microwave absorption performance within the temperature range of 25-600 °C, minimum reflection loss (RLmin) < -55 dB, and effective absorption bandwidth (EAB, RL < -10 dB) of 4 GHz. This work presents an effective approach for developing stable high-temperature microwave absorbers from thermal insulation ceramics.