Transversal Magnetic Anisotropy in Nanoscale PdNi-Strips

TL;DR

This study reveals that nanoscale PdNi strips exhibit unexpected transversal magnetic anisotropy, with the easy axis perpendicular to the strip direction, challenging conventional shape anisotropy expectations in spintronic device contacts.

Contribution

It provides the first detailed investigation of magnetic anisotropy in submicron PdNi strips, combining experimental techniques to reveal unexpected transversal easy axis.

Findings

Magnetic easy axis is in-plane but perpendicular to strip direction.

Anisotropic magnetoresistance confirms the transversal anisotropy.

Magnetic force microscopy supports the anisotropy orientation.

Abstract

We investigate submicron ferromagnetic PdNi thin-film strips intended as contact electrodes for carbon nanotube-based spintronic devices. The magnetic anisotropy and micromagnetic structure are measured as function of temperature and aspect ratio. Contrary to the expectation from shape anisotropy, magnetic hysteresis measurements of Pd0.3Ni0.7 on arrays containing strips of various width point towards a magnetically easy axis in the sample plane, but transversal to the strip direction. Anisotropic magnetoresistance measured on individual Pd0.3Ni0.7 contact strips and magnetic force microscopy images substantiate that conclusion.