Indications of superconductivity in doped highly oriented pyrolytic graphite

TL;DR

This study reports potential superconductivity in phosphorous-doped highly oriented pyrolytic graphite, with indications of onset temperatures above 100 K, influenced by doping level and structural damage.

Contribution

First evidence of possible high-temperature superconductivity in phosphorous-doped graphite using resistance measurements.

Findings

Superconductivity signals observed above 100 K in phosphorous-doped samples.

Superconductivity not observed in boron-doped samples.

Onset temperature depends on doping level and structural damage.

Abstract

We have observed possible superconductivity using standard resistance vs. temperature techniques in phosphorous ion implanted Highly Oriented Pyrolytic Graphite. The onset appears to be above 100 K and quenching by an applied magnetic field has been observed. The four initial boron implanted samples showed no signs of becoming superconductive whereas all four initial and eight subsequent samples that were implanted with phosphorous showed at least some sign of the existence of small amounts of the possibly superconducting phases. The observed onset temperature is dependent on both the number of electron donors present and the amount of damage done to the graphene sub-layers in the Highly Oriented Pyrolytic Graphite samples. As a result the data appears to suggest that the potential for far higher onset temperatures in un-damaged doped graphite exists.