New Bandgap Measurement Technique for a Half-Metallic Ferromagnet
New Bandgap Measurement Technique for a Half-Metallic Ferromagnet
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DOI：
10.1109/tmag.2014.2322912
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发表时间：
2014-11-01
影响因子：
2.1
通讯作者：
Hirohata, Atsufumi
中科院分区：
文献类型：
--
作者：
Alhuwaymel, Tariq F.;Abdullah, Ranjdar M.;Hirohata, Atsufumi
在本文中，我们报告了我们的新的光学方法测量的半金属铁磁体（HMF）的带隙是敏感的表面/界面和这些铁磁体的体区域取决于光的入射角和由此产生的穿透深度。以多晶Co_2FeSi-Heusler合金薄膜为例，在室温下测量了其禁带宽度。采用溅射法在MgO（001）和Si/SiO2衬底上制备了Co2 FeSi薄膜。圆偏振的红外光被用来激发相应的自旋极化电子，这些电子被Co2 FeSi Heusler合金的带隙有效地吸收。Co2 FeSi的带隙能量进行了反复测量，它被发现是类似于0.094 eV在RT。这种技术使我们能够直接表征HMF的自旋带隙。
In this paper, we report our new optical method for the measurement of the bandgaps of half-metallic ferromagnets (HMFs) that are sensitive to both surface/interface and bulk regions of these ferromagnets depending on the light incident angles and resulting penetration depth. We measured the bandgap of polycrystalline Co2FeSi Heusler alloy thin films at room temperature (RT) as an example. The Co2FeSi thin films were deposited on MgO(001) and Si/SiO2 substrates by sputter deposition. Circularly, polarized infrared light was used to excite the corresponding spin-polarized electrons, which were effectively absorbed by the bandgap of the Co2FeSi Heusler alloy. The Co2FeSi bandgap energy was repeatedly measured and it was found to be similar to 0.094 eV at RT. This technique allows us to characterize the spin bandgap of HMFs directly.