Analysis of L21-ordering in full-Heusler Co2FeSi alloy thin films formed by rapid thermal annealing

TL;DR

This paper introduces a new analysis method for evaluating atomic ordering in full-Heusler Co2FeSi alloy thin films, providing more accurate measurements of L21-ordering degrees using an extended model.

Contribution

The authors developed an extended model based on the Webster model to accurately quantify L21 atomic ordering, including correction for lower ordering structures.

Findings

High L21-ordering degree of 83% at 800°C annealing

Achieved B2-ordering of 97% in the films

Model provides direct evaluation of L21-ordering under various structures

Abstract

The authors developed a new analysis approach for evaluation of atomic ordering in full-Heusler alloys, which is extension of the commonly used Webster model. Our model can give accurate physical formalism for the degree of atomic ordering in the L21 structure, including correction with respect to the fully disordered A2 structure, i.e., the model can directly evaluate the degree of L21-ordering under a lower ordering structure than the complete B2-ordering structure. The proposed model was applied to full-Heusler Co2FeSi alloy thin films formed by rapid thermal annealing. The film formed at TA = 800 C showed a relatively high degree of L21-ordering of 83 % under a high degree of B2-ordering of 97 %.