Inter-particle spin-polarized tunneling in arrays of magnetite nanocrystals
Inter-particle spin-polarized tunneling in arrays of magnetite nanocrystals
复制标题
磁铁矿纳米晶体阵列中的颗粒间自旋极化隧道效应
DOI：
10.1016/j.jmmm.2008.12.012
复制
发表时间：
2009
影响因子：
2.7
通讯作者：
G. Markovich
中科院分区：
文献类型：
--
作者：
Nurit Taub;A. Tsukernik;G. Markovich
粒子间自旋极化隧穿测量在30 nm间距的金电极之间沉积的有机覆盖的磁铁矿纳米（NC）阵列。在阵列中的颗粒的磁矩的阻断温度（Tb）附近进行的磁阻（MR）测量，其相对较高（220 K），在几kOe的中等磁场下产生10-25%的负MR值。MR的场依赖性密切遵循的平方的膜的磁化强度和其电压依赖性表明最大的自旋极化周围的费米能级。这些发现表明，测量的MR是作为超顺磁性自旋极化器的单个磁铁矿NC之间的自旋极化隧穿的结果。
Inter-particle spin-polarized tunneling was measured in an organically capped magnetite nanocrystal (NC) array deposited between 30nm spaced gold electrodes. Magnetoresistance (MR) measurements performed around the blocking temperature (Tb) of the magnetic moments of the particles in the array, which was relatively high (220K), yielded negative MR values of the order of 10–25% under moderate magnetic fields of several kOe. The field dependence of the MR followed closely the square of the film's magnetization and its voltage dependence indicated maximal spin polarization around the Fermi level. These findings suggested that the measured MR is the result of spin-polarized tunneling between individual magnetite NCs acting as superparamagnetic spin polarizers.