A Novel Nano-Laminated GdBC with Excellent Electromagnetic Wave Absorption Performance and Ultra-High-Temperature Thermostability.

A novel nano-laminated GdBC material was successfully synthesized using GdH, BC, and C an in situ solid-state reaction approach for the first time. The formation process of GdBC was revealed based on the microstructure and phase evolution investigation. Purity of 96.4 wt.% GdBC was obtained at a low temperature of 1500 °C, while a nearly fully pure GdBC could be obtained at a temperature over 1700 °C. The as-obtained GdBC presented excellent thermal stability at a high temperature of 2100 °C in Ar atmosphere due to the stable framework formed by the high-covalence four-member and eight-member B-C rings in GdBC. The GdBC material synthesized at 1500 °C demonstrated a remarkably low minimum reflection loss (RL) of -47.01 dB (3.44 mm) and a broad effective absorption bandwidth (EAB) of 1.76 GHz. The possible electromagnetic wave absorption (EMWA) mechanism could be ascribed to the nano-laminated structure and appropriate electrical conductivity, which facilitated good impedance matching, remarkable conduction loss, and interfacial polarization, along with the reflection and scattering of electromagnetic waves at multiple interfaces. The GdBC, with excellent EMWA performance as well as remarkable ultra-high-temperature thermal stability, could be a promising candidate for the application of EMWA materials in extreme ultra-high temperatures.