Polyvinylpyrrolidone (PVP)/MnFe2O4 nanocomposite: Sol-Gel autocombustion synthesis and its magnetic characterization
2013 (English)In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 39, no 5, 5651-5658 p.Article in journal (Refereed) Published
A polyvinylpyrrolidone (PVP)/MnFe2O4 nanocomposite was prepared by the sol-gel autocombustion method and its structural, thermal, spectroscoppic, morphological and magnetic characterizations were done by XRD, FT-IR, TGA, SEM and VSM techniques. The presence of MnFe2O4 was confirmed by XRD and the size of crystallites was estimated to be 11 +/- 3 nm. Morphology analysis by SEM revealed spherical agglomerates of 15 nm. The magnetization curves confirm a superparamagnetic behavior with a blocking temperature of 287 K. The M-r/M-s value suggests the presence of uniaxial anisotropy in MnFe2O4 nanoparticles, instead of the expected cubic anisotropy according to the Stoner-Wohlfarth model. The effective magnetic anisotropy constant K-eff has been determined to be about 1.42 x 10(6) erg/cm(3) which is significantly higher than that of the bulk MnFe2O4. This suggests a strong magnetic coupling between magnetically ordered core spins and disordered surface spins of the nanoparticles in the nanocomposite.
Place, publisher, year, edition, pages
2013. Vol. 39, no 5, 5651-5658 p.
Sol-gel, Superparamagnetism, MnFe2O4, Magnetic nanomaterials
IdentifiersURN: urn:nbn:se:kth:diva-124029DOI: 10.1016/j.ceramint.2012.12.081ISI: 000318577600115ScopusID: 2-s2.0-84875735578OAI: oai:DiVA.org:kth-124029DiVA: diva2:633629
QC 201306272013-06-272013-06-252013-06-27Bibliographically approved