Effect of particle size on degree of inversion in ferrites investigated by Mössbauer spectroscopy

✍ Scribed by M. Siddique; N.M. Butt

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 562 KB
• Volume: 405
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2010.07.012

✦ Synopsis

M össbauer spectroscopy has been employed to investigate the cation distribution and degree of inversion in bulk and nanosized particles of CuFe 2 O 4 , MnFe 2 O 4 and NiFe 2 O 4 ferrites. The M össbauer spectra of all bulk ferrites show the complete magnetic behaviour, whereas nanoparticle ferrites are combination of ferromagnetic and superparamagnetic components. Moreover, the cation distribution in nanoparticle materials is also found to be different to that of their bulk counterparts indicating the particle size dependency. The inversion of Cu and Ni ions in bulk sample is greater than that of nanoparticles, whereas the inversion of Mn ions is less in bulk material as compared to the nanoparticles. Hence the degree of inversion (l) decreases in CuFe 2 O 4 and NiFe 2 O 4 samples, whereas it increases in MnFe 2 O 4 as the particle size decreases and thus shows the anomalous behaviour in this case. The nanoparticle samples also show paramagnetic behaviour due to superparamagnetism and this effect is more prominent in MnFe 2 O 4 .