Enhancement of the ferromagnetic order of graphite after sulphuric acid treatment

TL;DR

This study demonstrates that sulphuric acid treatment significantly enhances the ferromagnetic properties of graphite, including increased magnetization and AMR amplitude, suggesting potential for magnetic applications.

Contribution

It reveals that diluted sulphuric acid treatment can substantially improve ferromagnetic order in graphite materials, a novel approach for magnetic property enhancement.

Findings

Ferromagnetic magnetization of graphite increases after acid treatment.

AMR amplitude in graphite reaches values comparable to cobalt.

Acid treatment offers a simple method to enhance graphite's magnetic properties.

Abstract

We have studied the changes in the ferromagnetic behavior of graphite powder and graphite flakes after treatment with diluted sulphuric acid. We show that this kind of acid treatment enhances substantially the ferromagnetic magnetization of virgin graphite micrometer size powder as well as in graphite flakes. The anisotropic magnetoresistance (AMR) amplitude at 300 K measured in a micrometer size thin graphite flake after acid treatment reaches values comparable to polycrystalline cobalt.