Electrical Spin Injection in Multi-Wall carbon NanoTubes with transparent ferromagnetic contacts

TL;DR

This paper demonstrates electrical spin injection into multi-wall carbon nanotubes using ferromagnetic contacts, showing measurable magnetoresistance effects at low temperatures with potential implications for spintronic devices.

Contribution

First demonstration of electrical spin injection in MWNTs with transparent ferromagnetic contacts and low resistance devices at room temperature.

Findings

Hysteretic magneto-resistance observed at 2 K

Resistance difference of about 2% between magnetic configurations

Device resistances as low as 5.6 kΩ at 300 K

Abstract

We report on electrical spin injection measurements on MWNTs . We use a ferromagnetic alloy Pd$_{1-x}$Ni$_{x}$ with x $\approx$ 0.7 which allows to obtain devices with resistances as low as 5.6 $k\Omega$ at 300 $K$. The yield of device resistances below 100 $k\Omega$, at 300 $K$, is around 50%. We measure at 2 $K$ a hysteretic magneto-resistance due to the magnetization reversal of the ferromagnetic leads. The relative difference between the resistance in the antiparallel (AP) orientation and the parallel (P) orientation is about 2%.