Characterisation of Ferromagnetic Contacts to Carbon Nanotubes

TL;DR

This paper investigates various ferromagnetic materials and electrode shapes to optimize their use as contacts in carbon nanotube spintronic devices, demonstrating successful device fabrication and typical tunneling magnetoresistance behavior.

Contribution

It introduces a systematic study of different ferromagnetic thin films and electrode geometries for carbon nanotube spin devices, highlighting their micromagnetic properties and contact quality.

Findings

Permalloy, PdFe, and PdFe/Fe bilayers show suitable micromagnetic properties.

Devices exhibit tunneling magnetoresistance characteristic of spin valves.

Electrode shape influences contact quality and device performance.

Abstract

We present an investigation of different thin-film evaporated ferromagnetic materials for their suitability as electrodes in individual single-wall and multi-wall carbon nanotube-based spin devices. Various electrode shapes made from permalloy (Ni_{81}Fe_{19}), the diluted ferromagnet PdFe, and PdFe/Fe bilayers are studied for both their micromagnetic properties and their contact formation to carbon nanotubes. Suitable devices are tested in low-temperature electron transport measurements, displaying the typical tunneling magnetoresistance of carbon nanotube pseudo spin valves.