Fe implanted ferromagnetic ZnO

TL;DR

This study demonstrates that Fe ion implantation in ZnO can induce room-temperature ferromagnetism either via tiny Fe particles or through Fe ions incorporated into the lattice, creating potential for magnetic semiconductor applications.

Contribution

It reveals how implantation conditions determine whether Fe forms magnetic particles or acts as a dopant in ZnO, leading to different magnetic behaviors.

Findings

Tiny Fe particles cause ferromagnetism at high fluence and temperature.

Fe ions incorporated into ZnO create a diluted magnetic semiconductor.

Different implantation parameters lead to distinct magnetic mechanisms.

Abstract

Room-temperature ferromagnetism has been induced within ZnO single crystals by implant-doping with Fe ions. For an implantation temperature of 620 K and an ion fluence of 4x10^16 cm^-2, very tiny Fe particles, formed inside the host matrix, are responsible for the ferromagnetic properties. They were identified using synchrotron X-ray diffraction and Moessbauer spectroscopy. On the other hand, Fe ions implanted at a temperature of 253 K and an ion fluence of 4x10^15 cm^-2 are incorporated into the host matrix and develop a room temperature diluted magnetic semiconductor (DMS).