Induced spin-polarization of EuS at room temperature in Ni/EuS multilayers

摘要

Ni/EuS multilayers with excellent multilayer sequencing are deposited via e-beam evaporation on the native oxide of Si(100) wafers at 4 × 10~(-9) millibars. The samples have very small surface and interface roughness and show sharp interfaces. Ni layers are nanocrystalline 4-8 nm thick and EuS layers are 2-4 nm thick and are either amorphous or nanocrystalline. Unlike for Co/EuS multilayers, all Eu ions are in divalent (ferromagnetic) state. We show a direct antiferromagnetic coupling between EuS and Ni layers. At room temperature, the EuS layers are spin-polarized due to the proximity of Ni. Therefore, Ni/EuS is a candidate for room-temperature spintronics applications.