Generation and Detection of a Pure Spin Current using Co-Based Heusler-Alloy Spin Injector and Detector: Comparison of Co_2MnSi and Co_2FeSi

摘要

We have demonstrated the electrical generation and detection of giant pure spin currents using lateral spin-valve devices (LSVs) with highly-ordered Co_2FeSi (CFS) electrodes, where the CFS films were grown on Si(111) by low-temperature molecular beam epitaxy (LT-MBE). In this paper, we study the performance of LSVs with Co_2MnSi (CMS) electrodes. Unlike CFS, we cannot obtain high-quality CMS films on Si(111) even in the same LT-MBE condition. As a result, it is difficult for CMS grown on Si(111) to generate a large pure spin current in LSVs because of a relatively poor crystal quality with low spin polarization compared with CFS grown on Si(111).