Memory effects in exchange coupled Fe/Co3O4 nanocomposites

作者：Pati S P; Kumar S; Das D^*

来源：Materials Chemistry and Physics, 2012, 137(1): 303-309.

DOI：10.1016/j.matchemphys.2012.09.025

• Nanostructures
• Chemical synthesis
• Mossbauer spectroscopy
• Magnetometer
• Magnetic properties

Nanocomposites comprising a ferromagnet and an antiferromagnet have drawn attention recently because of their interesting physical properties and variety of technological applications. In the present work, structural, hyperfine and magnetic properties of Fe/Co3O4 nanocomposites prepared by a chemical route having 10-70 wt.% of Fe, have been investigated. XRD and TEM measurements confirmed polycrystalline nature of the samples having grain size in the nanometer regime. FTIR measurements show the presence of two bands of Co-O corresponding to Co2+ and Co3+. Mossbauer spectra recorded at room temperature confirm the presence of Fe in the blocked state. Presence of exchange bias at Fe-Co3O4 interfaces is confirmed by the magnetization measurements. Irreversibility in temperature dependent FC-ZFC measurements points to interface effect. Frequency dependent ac susceptibility measurements as well as memory effect observed in dc magnetization measurements indicate the superspin glass nature of the nanocomposites.

• 出版日期2012-11-15