Exploration of dielectric and microwave absorption properties of quaternary MAX phase ceramic (Cr2/3Ti1/3)3AlC2

Quaternary MAX phase ceramic (Cr2/3Ti1/3)3AlC2 was synthesized by in-situ reaction/hot-pressing process under protective argon atmosphere from Cr/Ti/Al/C mixture powders. To understand its microwave absorption properties, the dielectric parameters and reflection loss of the as-prepared (Cr2/3Ti1/3)3AlC2 were determined. It was revealed that the complex permittivity was related to both the content of (Cr2/3Ti1/3)3AlC2 powders in its mixture with paraffin and its particle size. (Cr2/3Ti1/3)3AlC2 powders exhibited attractive microwave absorption property in the case of narrow distribution of particle sizes. Meanwhile, the thickness of the tested matrix played an important role in microwave absorption property. When the sample thickness was 2.3 mm, its reflection loss was below −10 dB in the frequency range of 8.4–11.4 GHz, and the lowest reflection loss reached −36.5 dB at 10 GHz. So, it is confirmed that (Cr2/3Ti1/3)3AlC2 is promising microwave absorbent in X-band frequency range. It was confirmed that the absorption peak could be readily tailored by controlling its mean particle size and the thickness of tested matrix.