Article ID Journal Published Year Pages File Type
1617549 Journal of Alloys and Compounds 2011 4 Pages PDF
Abstract

This paper reports the magnetic properties of partially oxidized FeO nanoparticles (NPs) prepared using thermal decomposition of iron acetylacetonate at high temperature. X-ray diffraction (XRD) analysis confirmed that the resulting NPs comprise a mixture of wüstite and magnetite phases, which are subsequently confirmed using high resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) pattern. Magnetic properties were investigated using vibrating sample magnetometer (VSM), which exhibit superparamagnetic (SPM) behavior at room temperature. Alternatively, below 200 K, a large exchange bias field has been observed in field cooled mode whose magnitude increases with the decrease in measuring temperature attaining a maximum value of ∼2.3 kOe at 2 K accompanied by coercivity enhancement (∼3.4 kOe) and high field of irreversibility (>50 kOe). The results are discussed taking into account the role of interface exchange coupling on the macroscopic magnetic properties of the nanoparticles.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ageing effect in FeO nanoparticles and their transformation into core–shell FeO/Fe3O4 nanoparticles with enhanced chemical stability. ► The magnetic hystersis loop exhibit a set of interesting and unique features arising from the strong interfacial exchange coupling between the AFM core (FeO) and FiM (Fe3O4) shell viz., exchange bias and coercivity enhancement.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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