Achieving Tunable Microwave Absorbing Properties by Phase Control of NiCoMnSn Alloy Flakes

Abstract

Microwave absorption performance of metal alloys are highly dependent on their phase structures. However, the phase control of Ni–Mn-based alloys to achieve effective microwave absorption properties has been rarely reported. In this work, Ni43Co7Mn39Sn11 alloy flakes were fabricated by balling milling method, and the contents of γ phase in the flakes were tuned by the subsequent heat treatment process. The as-fabricated Ni43Co7Mn39Sn11 alloy flakes exhibited excellent tunable microwave absorption by control of their phase structures. The optimal reflection loss was lower, up to −56.4 dB at 8.8 GHz, and was achieved at a single thickness of 2.0 mm. This can be attributed to the optimal structure of Ni43Co7Mn39Sn11 alloy flakes by phase control, and thus achieving improved attenuation property and impedance matching. This study proved Ni43Co7Mn39Sn11 alloy flakes should be a promising microwave absorption material. It is also demonstrated that phase control is an effected strategy for optimal microwave absorption properties of metal alloys and may have some reference value for related studies.