Magnetic property modulation of Ni thin films transferred onto flexible substrates

•We report a robust and facile method to transfer Ni thin films onto flexible substrates.•Ni films were grown on water-soluble NaCl and successfully transferred onto PET substrates.•Strong magnetic anisotropy was observed for the films grown at high temperatures on NaCl substrates.•The magnetic anisotropy of the transferred films was modulated under bending. The integration of highly crystallized thin films on flexible plastic substrates has so far been limited by the instability of the plastic substrates at high growth temperatures. In this paper, we report a robust and facile method to transfer magnetic Ni thin films onto flexible substrates, which enables the imposition of strain on the substrates to take advantage of the magnetoelastic properties of the films. Ni thin films were grown on water-soluble NaCl substrates by sputtering at high temperature and, thereafter, successfully transferred onto flexible polyethylene terephthalate substrates. Magnetic hysteresis loops with strong magnetic anisotropy were observed for the films grown at high temperatures on NaCl substrates; the anisotropy increased after the films were transferred onto the plastic substrate. The magnetic anisotropy of the transferred films was modulated under bending; this phenomenon of magnetic modulation is more apparent at a small radius of curvature. The modulation of magnetic anisotropy in magnetic thin films on flexible substrates using our innovative thin film transfer method presents significant potential for application in future flexible multifunctional devices.