Hetero-epitaxial EuO Interfaces Studied by Analytic Electron Microscopy

TL;DR

This study uses advanced electron microscopy to analyze the atomic structure and chemical composition of EuO interfaces with silicon and YAlO3, revealing imperfections that could impact spintronic device performance.

Contribution

It provides detailed atomic-scale characterization of EuO interfaces, highlighting the presence of silicides and disorder that affect spin injection efficiency.

Findings

EuO|Si interfaces contain europium silicides and disordered regions.

Interface imperfections may reduce spin injection efficiency.

Atomic-resolution imaging reveals detailed interface chemistry.

Abstract

With nearly complete spin polarization, the ferromagnetic semiconductor europium monoxide could enable next-generation spintronic devices by providing efficient ohmic spin injection into silicon. Spin injection is greatly affected by the quality of the interface between the injector and silicon. Here, we use atomic-resolution scanning transmission electron microscopy in conjunction with electron energy loss spectroscopy to directly image and chemically characterize a series of EuO|Si and EuO|YAlO3 interfaces fabricated using different growth conditions. We identify the presence of europium silicides and regions of disorder at the EuO|Si interfaces, imperfections that could significantly reduce spin injection efficiencies via spin-flip scattering.