Direct determination of the surface termination in full Heusler alloys by means of low energy electron diffraction

TL;DR

This paper demonstrates how low energy electron diffraction (LEED) can non-destructively identify surface terminations in full Heusler alloys, which is crucial for optimizing their use in spintronic devices.

Contribution

It provides a method to distinguish and analyze different surface terminations of Heusler alloys using LEED patterns, including disordered and ordered phases.

Findings

LEED patterns can identify surface terminations of Heusler alloys.

Comparison with reference patterns allows determination of surface geometries.

Method applied to Co2MnSi and Co2Cr0.6Fe0.4Al examples.

Abstract

The performance of Heusler based magnetoresistive multilayer devices depends crucially on the spin polarization and thus on the structural details of the involved surfaces. Using low energy electron diffraction (LEED), one can non-destructively distinguish between important surface terminations of Co2XY full-Heusler alloys. We present an analysis of the LEED patterns of the Y-Z ,the vacancy-Z, the Co and the disordered B2 and A2 terminations. As an example, we show that the surface geometries of bulk L21 ordered Co2MnSi and bulk B2 disordered Co2Cr0.6Fe0.4Al can be determined by comparing the experimental LEED patterns with the presented reference patterns.