The Effect of d 10 Precious Elements on Structural, Magnetic and Elastic Properties of MnPt Alloy: A First-Principles Study

• Published in: Materials Vol. 17; no. 3
• Main Authors: Diale, Ramogohlo, Ngoepe, Phuti, Chauke, Hasani, Moema, Joseph, Phasha, Maje
• Format: Journal Article
• Language: English
• Published: Switzerland 23.01.2024
• Subjects: magnetic properties; Au; Ag; density functional theory; Mn50Pt50−xMx (M = Pd; elastic properties
• ISSN: 1996-1944

MnPt's exceptional stability and extremely high Néel temperature have generated a lot of interest in data storage applications. Previously, it was reported experimentally that the MnPt alloy shows ferromagnetic (FM) behavior at room temperature. In this study, the effects of partial substitution of Pt with Pd, Au, and Ag on magnetic properties is investigated using density functional theory. The stability of Mn Pt M (M = Pd, Au, Ag, x = 6.25, 12.5, 18.75) alloys was assessed by determining their thermodynamic, magnetic, and mechanical properties. The calculated lattice constants of Mn Pt agree well with available theoretical results. The Mn Pt M alloys' formability was assessed by measuring the thermodynamic stability using the heat of formation. It was found that B2 Mn Pt Pd alloys (0 ≤ x ≤ 18.75) are thermodynamically stable due to the negative heat of formation close to that of a pristine MnPt alloy. Based on the elasticity results, the B2 Mn Pt Pd is most likely to undergo martensitic transformation for the entire considered composition range. From the calculated values of the Poisson's ratio, it is shown that an increase in Pd, Ag, and Au effectively improves the ductility of the B2 Mn Pt M compounds. It was revealed that ferromagnetism is maintained with Pd addition but significantly reduced in the case of Au and Ag. Thus, this work showed that density functional theory can be exploited to propose new possible compositions for future magnets in spintronic applications.