Crystal structure, magnetic and microwave absorption properties of Ce_2−xSm_xFe₁₇N_{3−<i>δ</i>}/paraffin composites

Abstract

Crystal structure, magnetic and microwave absorption properties of Celsubg2-xl/subgSmlsubgxl/subgFelsubg17l/subgNlsubg3-δl/subg (x = 0.0, 0.1, 0.2, 0.3, 0.4) have been investigated. In these compounds, the substitution of Ce by Sm atoms, effectively modulating the ligcl/ig-axial andlig abl/ig-planar components of the magneto-crystalline anisotropy field, exerts a vital effect on the precession of magnetic moments. Thereby, the permeability and microwave absorption at high frequency are tuned. The easy magnetization directions (EMDs) of all the Celsubg2-xl/subgSmlsubgxl/subgFelsubg17l/subg (0≤x≤0.4) samples is in the ligabl/ig-plane, while for Celsubg2-xl/subgSmlsubgxl/subgFelsubg17l/subgNlsubg3-δl/subgsamples, it is in ligabl/ig-plane with x=0.0, 0.1, in cone with x=0.2, and finally parallel to ligcl/ig-axis with x=0.3, 0.4, respectively. Compared with other compounds, the one with cone-like anisotropy show superior microwave absorption properties due to better impedance match. The Celsubg1.8l/subgSmlsubg0.2l/subgFelsubg17l/subgNlsubg3-δl/subg/paraffin composite exhibits a maximum reflection loss (ligRLl/ig) (-39 dB) at 3.3 GHz with a thickness of 3.0 mm and is expected to be an excellent high frequency electromagnetic absorbing material with strong absorption and relatively small thickness.