C.N.R.-I.S.T.M. c/o Dipartimento di Scienze Chimiche, Università di Padova and INSTM, Via Marzolo 1, I-35131, Padova, Italy.
ACS Nano. 2013 Jan 22;7(1):857-66. doi: 10.1021/nn305459m. Epub 2013 Jan 2.
We report on the unprecedented direct observation of spin-polarization transfer across colloidal magneto-plasmonic Au@Fe-oxide core@shell nanocrystal heterostructures. A magnetic moment is induced into the Au domain when the magnetic shell contains a reduced Fe-oxide phase in direct contact with the noble metal. An increased hole density in the Au states suggested occurrence of a charge-transfer process concomitant to the magnetization transfer. The angular to spin magnetic moment ratio, m(orb)/m(spin), for the Au 5d states, which was found to be equal to 0.38, appeared to be unusually large when compared to previous findings. A mechanism relying on direct hybridization between the Au and Fe states at the core/shell interface is proposed to account for the observed transfer of the magnetic moment.
我们报告了在胶体磁等离子体 Au@Fe-氧化物核壳纳米晶体异质结构中前所未有的自旋极化转移的直接观察。当磁性壳层包含与贵金属直接接触的还原 Fe-氧化物相时，Au 域中会感应出磁矩。Au 态中载流子密度的增加表明伴随着磁矩转移发生了电荷转移过程。Au 5d 态的轨道磁矩与自旋磁矩的比值 m(orb)/m(spin) 被发现为 0.38，与之前的发现相比显得异常大。提出了一种机制，该机制依赖于核/壳界面处 Au 和 Fe 态之间的直接杂化，以解释观察到的磁矩转移。
