Anomalous magnetic behaviour of zinc and chromium ferrites without any hyperfine splitting
Two groups of ferrite namely zinc ferrite and chromium ferrite were synthesized by citrate precursor route in the size range of 8 to 35 nm. We have studied the structural and magnetic behaviour of these ferrites using X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and Mössbauer spectroscopic techniques. Our studies show that the nanocrystalline ferrites interact with the hand magnet strongly and give large magnetization in the VSM measurement. The maximum magnetization in the samples sensitively depends on the particle size of synthesized ferrites. We observed as large as 28 Am2/kg of magnetization in the zinc ferrite nanoparticles while that in chromium ferrite is around 11 Am2/kg. In spite of the large magnetization in the zinc ferrite nanoparticles we did not observe any hyperfine splitting even down to 12 K of temperature. Similar behaviour is also observed for chromium ferrite down to 16 K.
KeywordsMössbauer spectroscopy Ferrites Nanophase iron Magnetic nanoparticles
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- 8.Upadhyay, C.: In Controlled formation of nanosize spinel ferrites (4–15 nm) and their magnetic and structural studies, Ph.D. Thesis, IIT Kanpur (2003)Google Scholar