Modelling and measurement of magnetically soft nanowire arrays for sensor applications

0541691 - FZÚ 2022 RIV CH eng J - Journal Article
Ripka, P. - Grim, V. - Mirzaei, M. - Hraková, D. - Uhrig, J. - Emmerich, F. - Thielemann, C. - Hejtmánek, Jiří - Kaman, Ondřej - Tesař, Roman
Modelling and measurement of magnetically soft nanowire arrays for sensor applications.
Sensors. Roč. 21, č. 1 (2021), č. článku 3. E-ISSN 1424-8220
R&D Projects: GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : magnetic nanowires * soft magnetic wires * magnetic sensors
OECD category: Nano-materials (production and properties)
Impact factor: 3.847, year: 2021
Method of publishing: Open access

Soft magnetic wires and microwires are currently used for the cores of magnetic sensors. Due to their low demagnetization, they contribute to the high sensitivity and the high spatial resolution of fluxgates, Giant Magnetoimpedance (GMI), and inductive sensors. The arrays of nanowires can be prepared by electrodeposition into predefined pores of a nanoporous polycarbonate membrane. While high coercivity arrays with square loops are convenient for information storage and for bistable sensors such as proximity switches, low coercivity cores are needed for linear sensors. We show that coercivity can be controlled by the geometry of the array: increasing the diameter of nanowires (20 µm in length) from 30 nm to 200 nm reduced the coercivity by a factor of 10, while the corresponding decrease in the apparent permeability was only 5-fold. Finite element simulation of nanowire arrays is important for sensor development, but it is computationally demanding. While an array of 2000 wires can be still modelled in 3D, this is impossible for real arrays containing millions of wires. We have developed an equivalent 2D model, which allows us to solve these large arrays with acceptable accuracy.

Permanent Link: http://hdl.handle.net/11104/0319222