Angle dependence on the anisotropic magnetoresistance amplitude of a single-contacted Ni nanowire subjected to a thermo-mechanical strain

作者：Melilli G; Madon B; Wegrowe J E^*; Clochard M C

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2015, 365: 675-679.

DOI：10.1016/j.nimb.2015.09.055

• Track-etched membrane
• PVDF
• Magnetoresistance
• Magnetostriction
• Nanowire

The effects of thermoelastic and piezoelectric strain of an active track-etched beta-PVDF polymer matrix on an electrodeposited single-contacted Ni nanowire (NW) are investigated at the nanoscale by measuring the change of magnetization (i.e. using the inverse magnetostriction effect). The magnetization state is measured locally by anisotropic magnetoresistance (AMR). The ferromagnetic NW plays thus the role of a mechanical probe that allows the effects of mechanical strain to be characterized and described qualitatively and quantitatively. The inverse magnetostriction was found to be responsible for a quasi-disappearance of the AMR signal for a variation of the order of Delta T approximate to 10 K. In other terms, the variation of the magnetization due to the stress compensates the effect of external magnetic field applied on the NW resistance. The induced stress field in a single Ni NW was found 1000 time higher than the bulk stress field (due to thermal expansion measured on the PVDF). This amplification could be attributed to three nanoscopic effects: (1) a stress mismatch between the Ni NW and the membrane, (2) a non-negligible role of the surface tension on Ni NW Young modulus, and (3) the possibility of non-linear stress strain law. We investigate here the role of these different contributions using track-etched polymer membranes irradiated at various angles (alpha(irrad)) leading to, after electrodeposition, embedded Ni NWs of different orientations.

• 出版日期2015-12-15
• 单位中国地震局