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MA: Fachverband Magnetismus

MA 47: Poster III

MA 47.21: Poster

Thursday, March 21, 2024, 15:00–18:00, Poster D

Understanding the role of phonons in the ion induced phase transition of FeV — •Simon Rauls¹, Benedikt Eggert¹, Shadab Anwar², Tom Helbig¹, Kay Potzger², Jürgen Lindner², Jürgen Fassbender², Rantej Bali², and Heiko Wende¹ — ¹Faculty of Physics and CENIDE, University of Duisburg-Essen, Duisburg, Germany — ²Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany

Depending on the Fe concentration, the binary alloy Fe_1−xV_x is usually bcc-ordered and exhibits a low energy product as well as low intrinsic Gilbert damping, which makes it a candidate platform for low-loss spintronic devices. While an optimum V concentration of x=0.2 was found for the intrinsic Gilbert damping, at higher concentrations of x=0.4 the formation of a paramagnetic (PM), amorphous phase can be exploited. Using post-growth ion irradiation on the 40 nm thin-films, a phase transition from PM to FM can be achieved, enabling one-step writing of FM structures in a PM template, yielding a Gilbert damping parameter of 0.0027. In order to gain a deeper understanding of the aforementioned phase transition, Nuclear Inelastic Scattering experiments were performed, giving direct insights into the Fe-partial vibrational density of states of the as-grown and ion irradiated films. Along with Mössbauer spectroscopy, the interplay of chemical and structural disorder is deduced.
We acknowledge funding by the DFG through project no. 322462997 and the ESRF for granting the beamtime at beamline ID18.

Keywords: Transition Metal Alloys; Ion Irradiation; Gilbert Damping; Phonons; Disorder