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arXiv · 2208.11895

Magnetoresistive behaviour of ternary Cu-based materials processed by high-pressure torsion

M. Kasalo·S. Wurster·M. Stückler·M. Zawodzki·L. Weissitsch·R. Pippan·A. Bachmaier
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Abstract

Severe plastic deformation using high-pressure torsion of ternary Cu-based materials (CuFeCo and CuFeNi) was used to fabricate bulk samples with a nanocrystalline microstructure. The goal was to produce materials featuring the granular giant magnetoresistance effect, requiring interfaces between ferro- and nonmagnetic materials. This magnetic effect was found for both ternary systems; adequate subsequent annealing had a positive influence. The as-deformed states, as well as microstructural changes upon thermal treatments, were studied using scanning electron microscopy and X-ray diffraction measurements. Deducing from electron microscopy, a single-phase structure was observed for all as-deformed samples, indicating the formation of a supersaturated solid solution. However, judging from the presence of the granular giant-magnetoresistive effect, small ferromagnetic particles have to be present. The highest drop in room temperature resistivity (2.45% at 1790 kA/m) was found in Cu62Fe19Ni19 after annealing for 1 h at 400 °C. Combining the results of classical microstructural studies and magnetic measurements, insights into the evolution of ferromagnetic particles are accessible.

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M. Kasalo, S. Wurster, M. Stückler, M. Zawodzki, L. Weissitsch, R. Pippan, A. Bachmaier. 2022-08-25. Magnetoresistive behaviour of ternary Cu-based materials processed by high-pressure torsion. https://doi.org/10.1088/1757-899x%2F1249%2F1%2F012047

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