Electromagnetic and microwave absorption properties of iron pentacarbonyl pyrolysis-synthesized carbonyl iron fibers

Abstract

Carbonyl iron fibers synthesized at 300 °C exhibit a minimum RL of −58.1 dB and an effective absorption bandwidth of 5.66 GHz.

Enhanced Magnetization in a Frustrated Spin System by Ni+ Ion Beam Irradiation

“…The peaks at 711.3 eV and 725.3 eV were ascribed to the Fe 3+ 2p 2/3 and Fe 3+ 2p 1/2 electrons, respectively. 4,5,12 The binding energies at 707 eV and 719 eV would correspond to the metallic Fe state, but they do not seen in our data. Taking into account of the presence of O 1s peak in the survey spectra, we may suggest that some Fe elements on the surface of the samples before and after irradiation are oxidized to Fe 2 O 3 .…”

“…Three main diffraction peaks correspond to single cubic α-Fe (PDF#06-0696). 1,3,4,11 In both the samples, no other peaks due to impurities are detected. The inset of Fig.…”

“…Carbonyl iron (CI) powders are well known as microwave absorption materials due to their superior electric conductivity, high saturation magnetization, high Curie-temperature, and wide absorption bandwidth of 2−18 GHz. [1][2][3][4][5][6][7][8] In particular, a relatively high density and a high filling content make them more proper in electromagnetic wave absorption materials. From a point of view in magnetic properties, CI powders can be applied to magnetorheological suspensions where their favorable magnetic properties change Newtonian or pseudoplastic fluids in the absence of magnetic field to viscoplastic solid in the presence of magnetic field, creating chain-like structures along a direction of the field.…”

“…3 Also, particle size is one of the main factors in changing magnetic properties. 3,4,6,9,10 The distribution of the size may result in a distribution of the so-called blocking temperature, above which an unstable magnetization may establish due to thermal fluctuations. 6 Although there are many studies to investigate the electromagnetic wave absorption properties of CI powder, 1-4, 7, 8 a comprehensive study for the magnetic properties of CI powders has not been reported so far.…”

“…From a point of view in magnetic properties, CI powders can be applied to magnetorheological suspensions where their favorable magnetic properties change Newtonian or pseudoplastic fluids in the absence of magnetic field to viscoplastic solid in the presence of magnetic field, creating chain-like structures along a direction of the field. 4,5 Their superior controllability of the viscosity in the systems may thus successfully be exploited in industrial applications.…”