# Fabrication and electrical transport properties of embedded graphite microwires in a diamond matrix

## TL;DR

This paper reports the fabrication of embedded graphite microwires in diamond using ion beam irradiation and annealing, demonstrating their electrical properties and potential for designing embedded conductive circuits.

## Contribution

It introduces a method to produce and characterize embedded graphite microwires in diamond with controllable shapes and electrical properties.

## Key findings

- Embedded graphite wires exhibit resistivity close to bulk graphite.
- Wires show small negative magnetoresistance below 200 K.
- Method enables fabrication of embedded conductive circuits in diamond.

## Abstract

Micrometer width and nanometer thick wires with different shapes were produced $\approx 3~\upmu$m below the surface of a diamond crystal using a microbeam of He$^+$ ions with 1.8~MeV energy. Initial samples are amorphous and after annealing at $T\approx 1475$~K, the wires crystallized into a graphite-like structures, according to confocal Raman spectroscopy measurements. The electrical resistivity at room temperature is only one order of magnitude larger than the in-plane resistivity of highly oriented pyrolytic bulk graphite and shows a small resistivity ratio($\rho(2{\rm K})/\rho(315{\rm K}) \approx 1.275$). A small negative magnetoresistance below $T=200$~K was measured and can be well understood taking spin-dependent scattering processes into account. The used method provides the means to design and produce millimeter to micrometer sized conducting circuits with arbitrary shape embedded in a diamond matrix.