Advanced search
Start date
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Observation of superficial antiferromagnetism in Co3O4 polycrystals

Full text
von Dreifus, Driele [1, 2] ; Pereira, Ernesto Chaves [2] ; Aparecido de Oliveira, Adilson Jesus [1]
Total Authors: 3
[1] Univ Fed Sao Carlos, Dept Fis, Sao Paulo - Brazil
[2] Univ Fed Sao Carlos, Dept Quim, CP 676, Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: MATERIALS RESEARCH EXPRESS; v. 2, n. 11 NOV 2015.
Web of Science Citations: 2

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. (AU)

FAPESP's process: 09/54082-2 - Acquisition of a vibranting sample magnetometer coupled with a superconducting quantum interference device assensor (Squid-VSM) with cryogenic closed cycle
Grantee:Ernesto Chaves Pereira de Souza
Support type: Multi-user Equipment Program
FAPESP's process: 12/24025-0 - Magnetic, electrical and magnetostrictive properties of multiferroic composites and dilute magnetic semiconductors oxides
Grantee:Adilson Jesus Aparecido de Oliveira
Support type: Regular Research Grants
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC