We have studied the exchange bias (EB) effect and the magnetoresistance (MR) in Ni/NiO samples with different Ni content, obtained by mechanical milling from NiO and subsequent thermal treatments in hydrogen, inducing the formation of Ni nanocrystallites into the NiO matrix. The two phenomena appear strictly intertwined and thus the study of MR, involving spin-dependent and anisotropic contributions, helps to elucidate EB and vice versa. The observation of such coupling between EB and MR depends on the possibility of tailoring the samples’ structure and composition and the spin-glass like magnetic character of the NiO matrix strongly affects the physical mechanisms of both effects.
Magnetoresistance and exchange bias effect in nanogranular Ni/NiO
DEL BIANCO, Lucia;SPIZZO, Federico;TAMISARI, Melissa;
2011
Abstract
We have studied the exchange bias (EB) effect and the magnetoresistance (MR) in Ni/NiO samples with different Ni content, obtained by mechanical milling from NiO and subsequent thermal treatments in hydrogen, inducing the formation of Ni nanocrystallites into the NiO matrix. The two phenomena appear strictly intertwined and thus the study of MR, involving spin-dependent and anisotropic contributions, helps to elucidate EB and vice versa. The observation of such coupling between EB and MR depends on the possibility of tailoring the samples’ structure and composition and the spin-glass like magnetic character of the NiO matrix strongly affects the physical mechanisms of both effects.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
