Carvalho, Hugo Bonette deGodoy, Marcio Peron Franco dePais, Rafael Witter DiasMir, MirtaZevallos, Ângela Maria Ortiz deIikawa, FernandoBrasil, Maria José Santos PompeuChitta, Valmir AntônioFerraz, Wilmar BarbosaBoselli, Marco AurélioSabioni, Antônio Claret Soares2012-07-132012-07-132010CARVALHO, H. B. de et al. Absence of ferromagnetic order in high quality bulk Co-doped ZnO samples. Journal of Applied Physics, v. 108, n. 3, p. 033914-1/033914-5, 2010. Disponível em: <https://aip.scitation.org/doi/full/10.1063/1.3459885>. Acesso em: 27 fev. . 2019.00218979http://www.repositorio.ufop.br/handle/123456789/1111Bulk Zn1−xCoxO 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.en-USArtigo publicado em periodicoO periódico Journal of Applied Physics permite o depósito da versão PDF do editor em Repositório Institucional. Fonte: Sherpa/Romeo <http://www.sherpa.ac.uk/romeo/search.php?issn=0021-8979>. Acesso em: 28 fev. 2014.