Amorphous Slater-Pauling like behaviour in magnetic nanoparticles alloys synthesized in liquids

作者：Boyer Paul; Menard David^*; Meunier Michel

来源：Journal of Applied Physics, 2012, 112(6): 063910.

DOI：10.1063/1.4752267

Nanoparticles of Fe, Co, Ni, and their alloys, with an average diameter of 12 nm were synthesized in liquids using a laser. Their saturation magnetization exhibited a Slater-Pauling-like behaviour with two main differences compared to that expected in bulk materials. First, the amplitude of the magnetization was found to be roughly 5 times smaller. Second, the disappearance of the ferromagnetic (FM) behaviour occurred at Ni instead of the expected Ni0.6Cu0.4. The behaviour can be explained by the presence of non-magnetic oxidized shells which reduced the fraction of ferromagnetic atoms and induce through strain an amorphous structure in the metallic core. Annealing at 500 K leads to some crystallization of the particles and thus to a partial recovery of the expected magnetization.

• 出版日期2012-9-15