Magnetic and transport properties of sub-micron ferromagnetic wires

Abstract

Abstracb-Submicron CO wires with a variable width in the range from 0.2 to 2 pm and paired CO disks with a ameter in the range from 0.4 to 5 p m were o investigate the magnetoresistance effect in with the domain wall formation. A clear change in resist~~ty due to traversing domain wall along the wire the widths in both longitudinal and transverse magnetoresistance effects. The domain wall gives a negative contr~bution to the magnetoresistance effect. ~o n g i t u d i n~ magnetoresistance effects of paired CO disks show an anomalous increase in low fields below 20 kOe due to the peculiar vortex structure stabilized in the disk.

Negative Domain Wall Resistance in Ferromagnets

“…Our results agree with the experimental finding that the DW resistance can be negative [4][5][6][7][8]. We have shown that the sign of the DW resistance depends on the difference of scattering relaxation times, which can be positive or negative.…”

“…The experimental results [1][2][3][4][5][6][7][8] may thus originate from the same intrinsic semiclassical effect.…”

“…PACS numbers: 75.60.Ch, 73.50.Bk, A domain wall (DW) is the region between two ferromagnetic domains in which the direction of the magnetization rotates. A number of experiments have been conducted which show either an increase [1][2][3] or a decrease [4][5][6][7][8] of the resistance due to DWs compared to the resistance of a single-domain ferromagnet. These experiments have been done on thin films, structured thin films, and membranes in the diffusive transport regime, where the electron mean free path is shorter than the typical system size.…”

Quantitative study of magnetoresistance in patterned Ni80Fe20 wires

“…The domain wall gives a negative contribution to the magnetoresistance in submicron Co wires, evidenced in Ref. [4]. However, DW resistivity requires isolating the anisotropic magnetoresistance (AMR) and Lorentz magnetoresistance (MR) effect.…”

Magnetoresistive effects in planar NiFe nanoconstrictions

“…This has been observed through many experiments and numerous theoretical formulations [1][2][3][4][5] have been proposed. Despite these efforts, no unified theoretical picture exists and inconsistencies [6][7][8][9]11 within reported results remain unresolved. This is partly due to the difficulty in isolating a single domain wall and distinguishing its contribution from other effects such as the anisotropic magnetoresistance of the magnetic domains.…”