Tuesday, February 26, 2013

1302.5876 (G. F. Goya et al.)

Superparamagnetic Transition and Local Disorder in CuFe2O4 Nanoparticles    [PDF]

G. F. Goya, H. R. Rechenberg
We present X-ray diffraction (XRD), M\"ossbauer spectroscopy (MS) and d.c. magnetization measurements performed on ball-milled CuFe2O4 samples. The average particle size was found to decrease to the nanometer range after t=15 min of milling. Room temperature M\"ossbauer data showed that the fraction of particles above the blocking temperature TB increases with milling time, and almost complete superparamagnetic samples are obtained for = 7(2) nm. Magnetization measurements below TB suggest spin canting in milled samples. The values of saturation moment mu_S reveal that site populations are slightly affected by milling. M\"ossbauer resonant intensities are accounted for on the basis of local disorder of Fe3+ environments, and the development of sample inhomogeneities of CuxFe3-xO4 composition.
View original: http://arxiv.org/abs/1302.5876

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