Title :
Enhanced magnetization and cation distributions in nanocrystalline ZnFe2O4: a conversion electron Mossbauer spectroscopic investigation
Author :
Clark, Ted M. ; Evans, B.J.
Author_Institution :
Dept. of Chem., Michigan Univ., Ann Arbor, MI, USA
fDate :
9/1/1997 12:00:00 AM
Abstract :
The synthesis of nanocrystalline zinc ferrite (ZnFe2O 4) has been accomplished by a variety of chemical and mechanochemical techniques. An enhanced magnetization, 4-5 times that of bulk zinc ferrite, is observed for the nanoparticles regardless of the synthesis method. The hypothesis that the enhanced magnetization is due to partially inverted nanocrystalline zinc ferrite has been examined by transmission 57Fe Mossbauer spectroscopy (TMS), conversion X-ray Mossbauer spectroscopy (CXMS) and conversion electron Mossbauer spectroscopy (CEMS). Both TMS and CXMS data indicate differences in local structure between bulk and nanocrystalline samples, however they do not suggest that the samples are partially inverted. CEMS data are similar for both bulk and nanocrystalline samples, indicating similar cation distributions near the surface of nanocrystalline and bulk particles
Keywords :
Mossbauer effect; conversion electron spectra; crystal chemistry; crystal structure; ferrites; magnetic particles; magnetisation; nanostructured materials; particle size; zinc compounds; ZnFe2O4; bulk particles; bulk samples; cation distributions; chemical techniques; conversion X-ray Mossbauer spectroscopy; conversion electron Mossbauer spectroscopic investigation; conversion electron Mossbauer spectroscopy; enhanced magnetization; local structure; mechanochemical techniques; nanocrystalline ZnFe2O4; nanocrystalline zinc ferrite; surface; synthesis; transmission 57Fe Mossbauer spectroscopy; Annealing; Chemicals; Electrons; Ferrites; Magnetic properties; Magnetization; Nanoparticles; Spectroscopy; X-ray diffraction; Zinc;
Journal_Title :
Magnetics, IEEE Transactions on
