Epitaxial integration of the intrinsic ferromagnetic semiconductor GdN with silicon technology

TL;DR

This paper reports the successful epitaxial growth of the intrinsic ferromagnetic semiconductor GdN on silicon, advancing the integration of spintronics functionalities into silicon-based technology.

Contribution

It demonstrates the first epitaxial growth of GdN on silicon, addressing key challenges in integrating ferromagnetic semiconductors with existing silicon technology.

Findings

GdN films grown epitaxially on silicon substrates.

Characterization shows fully relaxed GdN with specific carrier density and mobility.

Magnetic behavior consistent with ferromagnetism.

Abstract

A major challenge for the next generation of spintronics devices is the implementation of ferromagnetic-semiconductor thin films as spin injectors and detectors. Spin-polarised carrier injection cannot be accomplished efficiently from metals, and coupled with the rarity of intrinsic ferromagnetic semiconductors this has driven intensive study of diluted magnetic semiconductors. Chief among these is the doped III-V compound (Ga,Mn)As. These materials suffer from a number of drawbacks; they (i) require magnetic-ion doping well above the solubility limit, and (ii) must be hole doped to above the degenerate limit, preventing independent control of the carrier concentration and charge sign. Here we demonstrate the first epitaxial growth of a recently-characterised intrinsic ferromagnetic semiconductor, GdN, on silicon substrates, providing an essential step on the way to integrate new spintronics functionalities into Si-based technology. The films have been characterised as regards their growth toward fully relaxed GdN, the density and mobility of their carriers, and their magnetic behaviour.