Spin-polarized field emission from Cr thin film deposited on W〈 001〉 tips
Spin-polarized field emission from Cr thin film deposited on W〈 001〉 tips
复制标题
W〈001〉尖端上沉积的 Cr 薄膜的自旋极化场发射
DOI：
10.1016/j.apsusc.2018.12.192
复制
发表时间：
2019
影响因子：
6.7
通讯作者：
Koichi Hata
中科院分区：
文献类型：
--
作者：
Shigekazu Nagai;Naoya Sakai;Kento Miyazaki;Tatsuo Iwata;Koichi Hata
为了通过场发射产生高且稳定的自旋极化电子束用于电子显微镜和光谱学，我们演示了在室温下无外部磁场的情况下，将Cr薄膜沉积在W< 0 0 1>尖端上的自旋极化场发射电子。当Cr厚度大于20 nm时，场发射电子的自旋极化率为35 ~ 50%。此外，获得了50%的最大自旋极化，这与第一性原理计算所期望的Cr（0 0 1）表面的值一致。极化方向在3 h内保持稳定，无突变。研究表明，与其他不稳定性受超顺磁性限制的铁磁材料相比，反铁磁Cr是一种合适的磁场发射极材料。
To generate high and stable spin-polarized electron beams by field-emission for applications to electron microscopy and spectroscopy, we demonstrated spin-polarized field-emitted electrons from a Cr thin film deposited on W< 0 0 1> tips at room temperature without an external magnetic field. A spin polarization of the field-emitted electrons of 35–50% was achieved when the Cr thickness was higher than 20 nm. In addition, a maximum spin polarization of 50% was achieved, consistent with the value for a Cr (0 0 1) surface expected by first-principles calculations. The polarization direction was also stable for 3 h with no abrupt change. This study indicates that antiferromagnetic Cr is proper cathode material for a field emitter than other ferromagnetic materials with an instability limited by superparamagnetic state.