Tunable microwave absorption properties of anisotropic Nd2Co17 micro-flakes

Abstract

An effect way for improving microwave absorption property was demonstrated in Nd2Co17 flake system without using any dielectric materials, and the mechanism were investigated. The Nd2Co17 flakes were prepared by arc-melting and ball-milling methods, and the anisotropy of Nd2Co17 flakes could be effectively tuned by changing milling time. The skin effect induced by eddy current could be suppress in the Nd2Co17 flakes. When the sample thickness d is smaller than 2.5 mm, an obvious increasing of the initial permeability and reflection loss (RL) could be observed with increasing the anisotropy of Nd2Co17 flakes. When the sample thickness d is larger than 2.5 mm, the minimum RL reached − 58.61 dB at 15.19 GHz with a matched thickness of 5.41 mm, which is mainly caused by the perfect impedance matching (Z ≈ 1) and 3λ/4 matching. An increasing of minimum thickness at RL = −20 dB could be observed with increasing milling time from 1 to 4 h. This work provides new opportunities for rare earth alloy magnetic materials in the field of microwave absorption.