Observation of superficial antiferromagnetism in Co3O4 polycrystals

We report on a systematic study about the magnetic properties of Co3O4 polycrystals with large size distribution (100-1200 nm) and the crystallite size of 68(4) nm on average. An antiferromagnetic transition at TN = 32 K, extensively reported in the literature for Co3O4, was observed. Furthermore, a...

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Bibliographic Details
Published in:Materials research express 2015-11, Vol.2 (11)
Main Authors: von Dreifus, Driele, Pereira, Ernesto Chaves, Oliveira, Adilson Jesus Aparecido de
Format: Article
Language:English
Subjects:
antiferromagnetic phase transition
magnetization process
spinel
Online Access:Get full text
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Summary:We report on a systematic study about the magnetic properties of Co3O4 polycrystals with large size distribution (100-1200 nm) and the crystallite size of 68(4) nm on average. An antiferromagnetic transition at TN = 32 K, extensively reported in the literature for Co3O4, was observed. Furthermore, another transition at Tt = 14 K, which is suppressed for H ≥ 35 kOe, was also identified. An increase in the magnetic susceptibility, as well as irreversibility between zero field cooled and field cooled data below Tt were observed. The non-detection of a coercive field below Tt, and the fact that Tt and TN are independent from the driven frequencies in ac magnetic measurements as a function of temperature, confirm that both peaks are associated to antiferromagnetic transitions.
ISSN:2053-1591
DOI:10.1088/2053-1591/2/11/116102