Authors: E Rozenberg
Publish Date: 2011/08/30
Volume: 13, Issue: 12, Pages: 7313-7316
Abstract
Some data on the dc and ac magnetic properties of electrondoped La1 − x Ca x MnO3 LCMO 05 ≤ x ≤ 08 sol–gel prepared nanoparticles with mean particle size of ~50 nm have been reported in a recent article Liu et al J Nanopart Res 132305 2011 In particular it is claimed that the charge ordering CO transition which is observed in the bulks disappears completely and the ferromagnetic FM one occurs in all the samples studied The authors also attributed the enhanced FM state with relatively large values of spontaneous magnetization in their samples to the good connection among the adjacent particles It is suggested in the comment through the present article that such claims seem to be doubtful and a natural reason for the above noted effects may be the systematic shift of a real composition Cadoping level from its nominal value due to eg oxygen nonstoichiometry of the considered samples The numerous uncertainties and obscurities are also characteristic of the article being commented upon
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