Structures and magnetic properties of wurtzite Zn1−xCoxO dilute magnetic semiconductor nanocomposites
2007; American Institute of Physics; Volume: 90; Issue: 10 Linguagem: Inglês
10.1063/1.2711180
ISSN1520-8842
AutoresTongfei Shi, Sanyuan Zhu, Zhihu Sun, Shiqiang Wei, Wenhan Liu,
Tópico(s)Gas Sensing Nanomaterials and Sensors
ResumoCobalt-doped ZnO dilute magnetic semiconductor nanocomposites Zn1−xCoxO with Co concentrations from 0.02 to 0.25 were prepared by the sol-gel method. The magnetic measurement shows paramagnetic behavior for all the samples. The structures of these composites were investigated by x-ray diffraction and fluorescence x-ray absorption fine structure spectroscopy. It is indicated that at low Co concentration (x⩽0.05), the Co atoms are incorporated into the ZnO lattice and located at the substitutional sites of the Zn atoms. At higher Co doping concentration (x⩾0.10), the secondary phase Co3O4 is precipitated. Correlating the magnetic behavior with the structural properties of the Zn1−xCoxO nanocomposites, the authors interpret the paramagnetism to be intrinsic in nature as a result of the low effective doping of Co in ZnO and the lack of oxygen vacancies.
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