Magnetotransport properties of iron microwires fabricated by focused electron beam induced autocatalytic growth

TL;DR

This study investigates the electrical and magnetotransport properties of iron microwires fabricated via focused electron beam induced autocatalytic growth, revealing metallic behavior, intrinsic anomalous Hall effect, and low-temperature negative magnetoresistance.

Contribution

It introduces a novel fabrication method combining FEBID and autocatalytic growth for iron microwires and characterizes their magnetotransport properties.

Findings

Metallic temperature dependence of resistivity with 88 microΩ·cm at room temperature

Intrinsic anomalous Hall effect with rhoAN proportional to rho_xx^2

Negative magnetoresistance of about 0.2% at low temperatures

Abstract

We have prepared iron microwires in a combination of focused electron beam induced deposition (FEBID) and autocatalytic growth from the iron pentacarbonyl, Fe(CO)5, precursor gas under UHV conditions. The electrical transport properties of the microwires were investigated and it was found that the temperature dependence of the longitudinal resistivity (rhoxx) shows a typical metallic behaviour with a room temperature value of about 88 micro{\Omega} cm. In order to investigate the magnetotransport properties we have measured the isothermal Hall-resistivities in the range between 4.2 K and 260 K. From these measurements positive values for the ordinary and the anomalous Hall coefficients were derived. The relation between anomalous Hall resistivity (rhoAN) and longitudinal resistivity is quadratic, rhoAN rho^2 xx, revealing an intrinsic origin of the anomalous Hall effect. Finally, at low temperature in the transversal geometry a negative magnetoresistance of about 0.2 % was measured.