Ferromagnetism in a Semiconductor with Mobile Carriers via Low-Level Nonmagnetic Doping

TL;DR

This paper demonstrates that nonmagnetic p-type doping of cubic iron pyrite induces ferromagnetism and high spin polarization, offering a new approach for spintronic materials without magnetic impurities.

Contribution

It introduces a novel doping strategy using nonmagnetic elements to achieve ferromagnetism and high spin polarization in semiconductors, bypassing magnetic impurity doping.

Findings

Doped cubic iron pyrite becomes ferromagnetic with p-type doping.

High spin polarization observed for tunneling and transport.

Phosphorus and arsenic are effective dopants.

Abstract

We show that doped cubic iron pyrite, which is a diamagnetic semiconductor, becomes ferromagnetic when $p$-type doped. We furthermore find that this material can exhibit high spin polarization both for tunneling and transport devices. These results are based on first principles electronic structure and transport calculations. This illustrates the use of $p$-type doping without magnetic impurities as a strategy for obtaining ferromagnetic semiconducting behavior, with implications for spintronic applications that require both magnetic ordering and good mobility. This is a combination that has been difficult to achieve by doping semiconductors with magnetic impurities. We show that phosphorus and arsenic may be effective dopants for achieving this behavior.