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Abstract：
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 Mn50Pt50-xMx (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 Mn50Pt50 agree well with available theoretical results. The Mn50Pt50-xMx alloys\' formability was assessed by measuring the thermodynamic stability using the heat of formation. It was found that B2 Mn50Pt50-xPdx 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 Mn50Pt50-xPdx 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 Mn50Pt50-xMx 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.
摘要：
MnPt的卓越稳定性和极高的Néel温度引起了人们对数据存储应用的极大兴趣。以前,据实验报道，MnPt合金在室温下显示出铁磁（FM）行为。在这项研究中,用Pd部分取代Pt的影响，Au,利用密度泛函理论研究了Ag的磁性能。Mn50Pt50-xMx(M=Pd,Au,Ag,x=6.25，12.5，18.75）合金通过确定其热力学来评估，磁性,和机械性能。计算的Mn50Pt50的晶格常数与可用的理论结果非常吻合。Mn50Pt50-xMx合金的成形性通过使用形成热测量热力学稳定性来评估。发现B2Mn50Pt50-xPdx合金（0≤x≤18.75）在热力学上是稳定的，因为形成的负热接近原始MnPt合金的负热。根据弹性结果，B2Mn50Pt50-xPdx在整个考虑的组成范围内最有可能经历马氏体相变。根据泊松比的计算值，结果表明，Pd的增加，Ag,和Au有效地提高了B2Mn50Pt50-xMx化合物的延展性。结果表明，添加Pd可保持铁磁性，但在Au和Ag的情况下显着降低。因此，这项工作表明，可以利用密度泛函理论为自旋电子学应用中的未来磁体提出新的可能组成。
