Tunable magnetic properties and microwave absorbing properties of (Nd1-xYx)2Fe17N3-δ

Abstract

Magnetic microwave absorbing materials of rare earth-transition metal (R-T) intermetallic compounds have the advantage of high absorbing performance, low matching thickness, and rich tunability. In this work, we report the magnetic and microwave absorbing properties of R-T intermetallic compounds (Nd_1-xY_x)₂Fe₁₇N_3-δ (x = 0 ∼ 1). The crystalline structure of these compounds transitions from Th₂Zn₁₇-type rhombohedral (for x  < 0.6) to Th₂Ni₁₇-type hexagonal (for x  > 0.8) as the composition varies, attributed to the reduction in lattice volume. The saturation magnetization (M_s) of the (Nd_1-xY_x)₂Fe₁₇N_3-δ remains almost unchanged as x changes. However, the out-of-plane anisotropy field decreases significantly from 111kOe to 25kOe while x increases. The high-frequency magnetic permeability of the material is also significantly elevated and thus leads to a significant enhancement in microwave absorbing performance. A 5.8 GHz maximum effective absorption bandwidth (EAB, RL < -10 dB) could be achieved within a thickness of only 1.1 mm for Y₂Fe₁₇N_3-δ(x = 1)/paraffin composite primarily due to its heavy magnetic loss. Furthermore, the minimum reflection loss (RL) reaches −49 dB at 6.6 GHz with a thickness of 2.2 mm. The tunable magnetic properties and excellent microwave absorbing performances of (Nd_1-xY_x)₂Fe₁₇N_3-δ make it a strong contender for applications in high-performance microwave absorbing materials.