Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 55: Electron theory and micromagnetism

MA 55.1: Vortrag

Freitag, 5. April 2019, 09:30–09:45, H38

Ab-initio calculations of the spin wave stiffness constant for permalloy doped with V, Gd, and Pt — •Ondřej Šipr¹, Sergey Mankovsky², and Hubert Ebert² — ¹Institute of Physics, Czech Academy of Sciences, Praha — ²Ludwig-Maximilians-Universität München

The modification of the properties of magnetic materials by doping is a promising and intensively studied way to make progress in device technology and spintronics. A very important system in this respect is permalloy Fe₂₀Ni₈₀ — not only because of its high magnetic permeability but also because of its transport properties characterized by a high and low electrical conductivity in the majority and minority spin channel, respectively. As the spin dynamics of materials is governed by the spin wave stiffness D or the closely connected exchange stiffness A, we perform ab-initio investigation of this quantity for permalloy (Py) doped with V, Gd, and Pt. Our study is based on electronic structure calculations by means of the Korringa-Kohn-Rostoker (KKR) Green’s-function method, with disorder treated within the coherent potential approximation (CPA). For Gd as a dopant the open core formalism was employed. The calculated results are in a good agreement with experiment [Lepadatu et al PRB 81, 020413 (2010) and APL 97, 072507 (2010); Yin et al IEEE Magn. Lett. 8, 3502604 (2016); Hrabec et al PRB 93, 014432 (2016)], correctly reproducing the trends when the chemical type (V, Gd, or Pt) or the concentration (1–10 %) of the dopant are changed.