Artículos de revistas
Absence of ferromagnetic order in high quality bulk Co-doped ZnO samples
Registro en:
JOURNAL OF APPLIED PHYSICS, v.108, n.3, 2010
0021-8979
10.1063/1.3459885
Autor
CARVALHO, H. B. de
GODOY, M. P. F. de
PAES, R. W. D.
MIR, M.
ZEVALLOS, A. Ortiz de
IIKAWA, F.
BRASIL, M. J. S. P.
CHITTA, V. A.
FERRAZ, W. B.
BOSELLI, M. A.
SABIONI, A. C. S.
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Bulk Zn(1-x)Co(x)O samples were synthesized via standard solid-state reaction route with different Co molar concentrations up to 21%. A detailed microstructural analysis was carried out to investigate alternative sources of ferromagnetism, such as secondary phases and nanocrystals embedded in the bulk material. Conjugating different techniques we confirmed the Zn replacement by Co ions in the wurtzite ZnO structure, which retains, however, a high crystalline quality. No segregated secondary phases neither Co-rich nanocrystals were detected. Superconducting quantum interference device magnetometry demonstrates a paramagnetic Curie-Weiss behavior with antiferromagnetic interactions. We discuss the observed room temperature paramagnetism of our samples considering the current models for the magnetic properties of diluted magnetic semiconductors. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3459885] 108 3 FAPEMIG Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FAPEMIG_Brasil CNPq_Brasil FAPESP_Brasil