Organic magnetic molecules are potential candidates to act as spin filters owing to the spin degeneracy caused by unpaired electron. Based on density functional theory in combination with non-equilibrium Green’s function (NEGF-DFT) method, we study the spin-filtering capability employing the much cultivated and stable organic radicals nitronyl nitroxide (NN) and oxo-verdazyl (OVER). The spin-resolved electronic transportations across the organic radicals connected to the framework of pentacene is investigated by bridging the radical-pentacene moiety between gold electrodes. Unexpectedly, both the stable radicals do not act as efficient spin filters due to the orthogonal arrangement of radical moiety w.r.t pentacene core. On the other hand, the planar arrangement of the radical attached to the pentacene via ethynyl spacer enhances the spin polarization due to much larger delocalization of spin density on pentacene core. Further, the introduction of methyl radical provides an alternative way to use such stable radicals for efficient spin filtering.

由于不成对电子引起的自旋简并性，有机磁性分子是用作自旋滤光片的潜在候选物。基于密度泛函理论，结合非平衡格林函数（NEGF-DFT）方法，我们研究了利用大量耕种且稳定的有机基硝酰基硝基氮（NN）和氧代-草并二氮杂（OVER）的自旋过滤能力。通过桥接金电极之间的自由基并五苯部分，研究了与并五苯骨架相连的有机自由基上自旋分辨的电子传输。出乎意料的是，由于并五苯核的自由基部分的正交排列，所以两个稳定的自由基都不充当有效的自旋过滤器。另一方面，通过乙炔基间隔基连接到并五苯的自由基的平面排列由于并五苯核上自旋密度的更大的离域而增强了自旋极化。此外，甲基自由基的引入提供了使用这种稳定的自由基进行有效的自旋过滤的替代方法。