Size dependence of ferromagnetism in gold nanoparticles: Mean field results

作者：Michael Fredrick^*; Gonzalez Carlos; Mujica Vladimiro; Marquez Manuel; Ratner Mark A

来源：Physical Review B, 2007, 76(22): 224409.

DOI：10.1103/PhysRevB.76.224409

In this paper, a simple spin-spin Ising interaction model for the surface ferromagnetism is combined with the bulk Au diamagnetic response to model the size dependence of the magnetization of a Au nanoparticle. Using the maximum entropy formalism, we obtain the average temperature dependent magnetization within a mean field model. Our results qualitatively reproduce recent experimental observations of size-dependent magnetization of Au nanoparticles in which the ferromagnetic moment of thiol-capped nanoparticles is seen to increase for diameters larger than 0.7 nm, peaking at approximately 3 nm, and subsequently decreasing as the particle diameter increases further.

• 出版日期2007-12
• 单位西北大学