Article ID Journal Published Year Pages File Type
5454859 Materials Characterization 2017 7 Pages PDF
Abstract
The natural composite of tubular mineral halloysite Al2Si2O5(OH)4 and nanoparticles of poorly crystallized or amorphous hematite Fe2O3 were investigated by means of transmission electron microscopy, electron spin resonance, Mössbauer spectroscopy and quantitatively characterized in measurements of low temperaturemagnetic susceptibility χ. The diamagnetic response χdiaof the halloysite nanotubes is superimposed on complex paramagnetic behavior χpara due to the presence of iron impurities in various aggregate forms. The low temperature upturn in χ(T) dependence is ascribable to isolated Fe3 + ions substituting Al3 + ions, the step-like anomaly at Tg ~ 80 K is the signature of glassy magnetic order in nanosized inclusions of amorphous hematite.
Related Topics
Physical Sciences and Engineering Materials Science Materials Science (General)
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