Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 42: Thin films – anisotropy

MA 42.4: Vortrag

Donnerstag, 15. März 2018, 10:15–10:30, EB 301

Effect of N, C and B interstitials on the structural and magnetic properties of alloys with Cu₃Au-structure — •Ingo Opahle, Harish Kumar Singh, and Hongbin Zhang — TU Darmstadt, Germany

High-throughput density functional calculations are used to investigate the effect of interstial B, C and N atoms on the stability, structural and magnetic properties of 21 reported alloys crystallizing in the cubic Cu₃Au structure. For 29 alloy/interstitial combinations the formation of stable interstitial alloys with interstitial concentrations above 5% is expected. The majority of stable interstitials prefers the anti-perovskite structure. It is shown that interstitials can have a huge impact on the magneto-crystalline anisotropy energy (MAE) when the cubic symmetry is broken. For MnNi₃ and FeNi₃ interstitial N leads to a tetragonal distortion with a moderate uniaxial MAE. Mn₃XN_x (X=Rh, Ir, Pt and Sb) are identified as alloys with strong magneto-crystalline anisotropy. For Mn₃Ir interstitial N leads to a huge enhancement of the MAE. It is expected that N has also a strong influence on the MAE of amorphous Mn₃Ir, which is one of the state-of-the-art materials for exchange bias in hard magnetic films. The impact of the N interstitials on the MAE is discussed at hand of the electronic structure.