Spin canting and magnetic transition in Ni_xZn_(1-x)Fe_2O_4 (x=0.0, 0.5 and 1.0) nanoparticles

摘要

Nanoparticles of Ni_xZn_(1-x)Fe_2O_4(x=0.0, 0.5 and 1.0) have been synthesized via co-precipitation method and studied thestructural and magnetic properties. Rietveld refinement of X ray diffraction data of as synthesized samples revealthat the samples have mixed spinel structure with space group Fd-3m. The lattice parameter of the samples decreases as doping concentration of Ni ions increases. Magnetic measurements show paramagnetic to ferrimagnetic transition at room temperature on Ni doping in ZnFe_2O_4 nanoparticles. The magnetic measurements also show spin canting in samples possibly due to their nanocrystalline nature. The spin canting angles have been calculated with the help of Yafet-Kittel (Y-K) model. Furthermore, the Law of approach (LA) fitting of M-H curves indicates that the samples are highly anisotropicin nature. The Arrot plots of as synthesized samples also indicate the paramagnetic to ferrimagnetic transition. The correlation between the structural and observed magnetic properties of Ni_xZn_(1-x)Fe_2O_4(x=0.0, 0.5 and 1.0) nanocrystals will be described and discussed in this paper.