Magnetic properties of nitrogen doped diamond: A first principles study

TL;DR

This study uses density functional theory to investigate how nitrogen doping and vacancies in diamond influence its magnetic and electronic properties, revealing stable magnetism only with specific defect configurations and potential for spintronics.

Contribution

It demonstrates that stable magnetism in N-doped diamond arises specifically from nitrogen-vacancy centers, providing insights into defect-induced magnetism in diamond materials.

Findings

Magnetism appears only with nitrogen-vacancy centers.

Magnetic moment increases linearly with NV centers.

NV-center systems exhibit p-type semiconducting behavior.

Abstract

The magnetic and electrical properties of nitrogen doped diamond system have been studied within the framework of a density functional theoretical approach. Spin-polarised calculations reveal that only the nitrogen doped system with adjacent carbon vacancies (NV-centre) leads to stable magnetism in N-doped diamond. The magnitude of the induced magnetic moment increases linearly with increasing number of NV centres in the system. This result explains earlier experimental reports suggesting unconventional magnetism in N-doped pristine diamond. The 2p-orbital electrons of the three carbon atoms adjacent to the vacancy contribute to the magnetic moment in the system. Notably, lone N at the lattice site in diamond system fails to induce any significant moment, whearas the C-vacancy and N-interstitial positions induce magnetic moment in the diamond system. Moreover, the NV-center system has p-type semiconducting characteristics, making it a potential candidate for spintronics applications. To quantify the feasibility of different systems, the magnetic moment, ground state free energy, Fermi energy and defect formation energy were calculated for each structure.