[10a-M101-1~8] 10.1 Emerging materials in spintronics and magnetics (including fabrication and charactrization methodologies)

[10a-M101-8] Spin splitting of EuO/Si spin filter junctions with atomically sharp interface

〇Rento Ohsugi¹, Hiroo Omi^1,2, Yoshiharu Krockenberger¹, Akira Fujiwara¹ (1.NTT Basic Research Lab., 2.NTT Nano Photonics Center)

Keywords:Europium oxide, Si, Spin filter

Spin injection into Si is the fundamental process for operations of Si-based spintronic devices. An effective way for the spin injection is the use of spin-filtering effect working at the interface between ferromagnetic oxides and Si. However, to realize an efficient spin-filtering, the ferromagnetic materials have to be grown on Si with atomically sharp interfaces. Recently, we have reported that ferromagnetic europium oxide (EuO) has been epitaxially grown on Si(111) substrates. Here, we fabricated EuO tunnel junctions with the abrupt interfaces, and derived spin-splitting of tunnel barriers of EuO films on Si.
We first measured J-V curves of the devices in a measurement configuration. Next, to obtain the temperature and thickness dependences of the tunneling barrier heights, the J-V curves were fitted using the spin-selective Simmons model. The spin-dependent barrier heights () show spin-splittings of tunnel barriers below the Curie temperature of 35 K. A spin polarization (P) of 97% (20 K) is calculated by the J-V curve fittings. The EuO(111)/Si(111) structure with the atomically sharp interfaces can be used as an efficient spin-filter on Si.