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MA: Fachverband Magnetismus
MA 10: Caloric Effects in Ferromagnetic Materials
MA 10.5: Vortrag
Montag, 20. März 2017, 16:15–16:30, HSZ 04
Strain-dependent magnetization measurements of epitaxial Ni-Mn-Ga-Co thin films on piezoelectric substrates — •Benjamin Schleicher1,2, Stefan Schwabe1, Robert Niemann1, Anett Diestel1, Ruben Hühne1, Kornelius Nielsch1, Ludwig Schultz1,2, and Sebastian Fähler1,2 — 1IFW Dresden, P.O Box 270116, D-01171 Dresden, Germany — 2TU Dresden, Institute of Solid State Physics, D-01062 Dresden, Germany
Heusler alloys such as Ni-Co-Mn-X (X=Ga, In, Sb, Sn), which show an inverse magnetocaloric effect, are promising materials for solid state cooling. Additionally to high external magnetic fields, the phase transition can also be induced by the application of mechanical stress. This can be realized with an electric field when the magnetocaloric thin film is deposited on a piezoelectric substrate. Thin films are of particular interest since their high surface-to-volume ratio allows fast heat transfer and high cycling frequencies, which leads to higher cooling power using less material. We present an investigation of sputtered epitaxial Ni-Mn-Ga-Co thin films on piezoelectric PMN-PT substrates [1]. Temperature dependent texture and magnetic measurements show the structural and magnetic phase transition in the material. The influence of temperature, magnetic field and mechanical stress on the magnetization of the Ni-Mn-Ga-Co thin film was investigated with a dedicated SQUID setup. In particular, the stress variation was achieved by applying an electric field to the multiferroic stack. This work is supported by DFG through SPP 1599 www.FerroicCooling.de. [1] B. Schleicher et al., J. Appl. Phys. 118 053906 (2015)