Template-assisted synthesis and novel microwave absorption properties of superparamagnetic 2D-nanolamellar Fe3O4

Nanolamellar Fe3O4 (magnetite) (NLM) was synthesized by template method. The repeat periodicity of the 2-dimensional nanolamellar structure was 3.72 nm. NLM exhibited a superparamagnetic characteristic with the saturated magnetization 34.8 emu/g. The results showed NLM possessed properties of novel microwave absorption in the frequency range 1–18 GHz. An obvious multiple-reflection loss phenomenon was observed with the increase of matching thickness. For example, 8 reflection loss peaks could be found on the reflection loss curve of NLM/paraffin composite with 50 wt.% NLM at the thickness of 28.0 mm. Compared with NLM/paraffin composite with 75 wt.% NLM, the microwave absorption property of the composite with 50 wt.% NLM was confirmed to be inferior in the 1–10 mm thickness range but superior in the 10–30 mm thickness range. The lowest reflectivity was −46.6 dB obtained from NLM/paraffin composite with 75 wt.% NLM at 7.0 mm thickness. The NLM is a promising microwave absorber.