Tuning the surface anisotropy in Fe-doped NiO nanoparticles

• DOI: 10.1039/c3nr04926d
• Publication Date: 2013-10-04T10:33:33Z
• Authors: K. O. Moura; R. J. S. Lima; A. A. Coelho; E. A. Souza-Junior; J. G. S. Duque; C. T. Meneses
• Keywords: Exchange bias; Rietveld Refinement; Superparamagnetism; Non-blocking I/O

Ni(1-x)FexO nanoparticles have been obtained by the co-precipitation chemical route. X-ray diffraction analyses using Rietveld refinement shown a slight decrease in microstrain and mean particle size as function of Fe content. The zero-field-cooling (ZFC) field-cooling (FC) magnetization curves show superparamagnetic behavior at high temperatures low temperature peak (at T = 11 K), which is enhanced with increasing concentration. Unusual coercive field region an exchange bias were also observed. A concentration induces increase field. We argue that these behaviors can be linked strengthening surface anisotropy caused incorporation ions.