Open AccessSynthesis and electromagnetic properties of Fe/SiO 2 yolk/shell nanospheres with improved oxidation resistance
Author(s) -
Fu LiShun,
Jiang JianTang,
Xu ChengYan,
Gong YuanXun,
Zhen Liang
Publication year - 2013
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2013.0009
Subject(s) - materials science , reflection loss , shell (structure) , microwave , chemical engineering , composite material , composite number , physics , quantum mechanics , engineering
Nearly monodispersed Fe/SiO 2 yolk/shell nanospheres with an average diameter of about 250 nm were synthesised by hydrogen‐thermal reduction of Fe 3 O 4 /SiO 2 precursor nanospheres. The morphology of products and precursors was characterised in three stages of preparation. Electrical conductivity magnetic properties and electromagnetic properties in the microwave band of Fe/SiO 2 yolk/shell nanospheres were investigated. The eddy current effect in Fe/SiO 2 yolk/shell nanospheres was effectively suppressed because of separation of ultrafine iron particles by silica shells, indicating that the eddy current effect can be suppressed only by separating iron particles and it is not related to the interface of iron and sillica. A reflection loss of −12.5 dB and an effective absorption band with a bandwith of 3.3 GHz were simultaneously obtained for Fe/SiO 2 yolk/shell nanospheres‐containing coatings with thickness of 2 mm. Compared with bare Fe particles obtained from Fe 3 O 4 precursor nanospheres, oxidation resistance of Fe/SiO 2 yolk/shell nanospheres was improved because of the existence of silica shells.