Magnetically driven short-range order can explain anomalous measurements in CrCoNi

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Chemical short-range order (CSRO) in multi-principal element alloys (MPEAs) like CrCoNi is debated.
• Understanding CSRO is crucial for predicting and designing MPEA properties.

Purpose of the Study:

• Investigate the origins and impact of CSRO in CrCoNi.
• Clarify the role of magnetic interactions in CSRO formation.
• Provide a predictive model for CSRO in MPEAs.

Main Methods:

• Utilized first-principles calculations.
• Developed ordering models based on magnetic interactions.
• Compared model predictions with experimental data on magnetization and atomic volumes.

Main Results:

• CSRO in CrCoNi originates from magnetic interactions, specifically repulsion between like-spin Co-Cr and Cr-Cr pairs.
• A magnetically aligned sublattice of second-nearest-neighbor Cr atoms contributes to the ordering.
• The developed ordering models successfully predict anomalous experimental measurements across various compositions.

Conclusions:

• Magnetic interactions are fundamental to CSRO in CrCoNi.
• The findings explain previously anomalous experimental observations.
• CSRO driven by magnetic interactions may be more prevalent in MPEAs than previously thought.