Berlin 2012 – scientific programme

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MA: Fachverband Magnetismus

MA 39: Micro- and Nanostructured Magnetic Materials I

MA 39.3: Talk

Thursday, March 29, 2012, 10:00–10:15, EB 202

Structure, microstructure and magnetic properties of electrodeposited Fe₇₀Pd₃₀ nanowires — •Veronika Haehnel^1,2, Christine Mickel¹, Heike Schlörb¹, Sebastian Fähler¹, and Ludwig Schultz^1,2 — ¹IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany — ²TU Dresden, Faculty of Mechanical Engineering, Institute of Material Science, 01062 Dresden, Germany

Fe-Pd alloys at about 30 at.% Pd show excellent functional properties. The scientific and technological interest is focused on these martensitic transforming alloys as they exhibit the magnetic shape memory effect (MSM). The expected strains of up to several percent make them perfect candidates for nanoactuators or sensors. Due to the reduced dimensions actuation frequencies should increase. Also a double maximum strain compared to thin films is expected for the novel “stray field induced microstructure”-actuation mode, because shape anisotropy favors only one easy axis along the nanowire axis.

In this study we use the cost and time efficient method of electrodeposition within nanoporous aluminum oxide templates to prepare Fe-Pd nanowires. A complexed electrolyte of Fe³⁺ and Pd²⁺ ions and an alternating potential regime is necessary to achieve continuous, almost defect free nanowires exhibiting a composition close to the Fe₇₀Pd₃₀ alloy. TEM and structural investigations reveal a bcc Fe-Pd structure and nanocrystalline grain sizes. Magnetic properties are controlled by shape anisotropy as well as magnetostatic interactions between neighboring nanowires. These results represent a promising starting point for future research toward MSM nanoactuators.