Magnetic and microwave absorbing properties of Ce-Co-based alloy powders driven with lanthanum content

Abstract

The composites of Ce-Co-based alloys doped with La content were fabricated via a vacuum arc melting method. The influences of La addition on microstructure, electromagnetic parameters, magnetic property and microwave absorbing property were measured by the corresponding equipment. The morphology characteristics manifest that all samples display sheet structure, and the average particle size of alloy powders increases with increasing La content. The saturation magnetization (Ms) decreases with increasing La addition as a whole. The minimum reflection loss (RL) of La0.4Ce1.6Co17 alloy powder about −42.29 dB can be obtained about −42.29 dB at 7.84 GHz with the matching thickness of 1.8 mm, and the corresponding effective bandwidth can achieve about 2.24 GHz. In addition, the minimum RL frequency moves towards a lower frequency region as the La content increases. The minimum RL of La0.3Ce1.7Co17 alloy powder is less than −20 dB ranging from 1.2 to 2.4 mm in the whole 4–16 GHz. The maximum bandwidth can reach about 4.88 GHz at the given thickness of 1.2 mm. In general, these all indicate that the La addition is beneficial to improving the microwave absorbing performance in both effective bandwidth and absorption intensity.