A key to room-temperature ferromagnetism in Fe-doped ZnO: Cu

TL;DR

This paper reports the synthesis of room-temperature ferromagnetic ZnO semiconductors doped with Fe and Cu, achieving high Curie temperatures and notable magnetic properties, advancing potential spintronic applications.

Contribution

It demonstrates that Cu doping is essential for inducing room-temperature ferromagnetism in Fe-doped ZnO, with record Curie temperatures and magnetic responses.

Findings

Curie temperature up to 550 K in Zn0.94Fe0.05Cu0.01O

Room-temperature saturation magnetization of 0.75 μB per Fe

Large magnetoresistance observed below 100 K

Abstract

Successful synthesis of room-temperature ferromagnetic semiconductors, Zn$_{1-x}$Fe$_{x}$O, is reported. The essential ingredient in achieving room-temperature ferromagnetism in bulk Zn$_{1-x}$Fe$_{x}$O was found to be additional Cu doping. A transition temperature as high as 550 K was obtained in Zn$_{0.94}$Fe$_{0.05}$Cu$_{0.01}$O; the saturation magnetization at room temperature reached a value of $0.75 \mu_{\rm B}$ per Fe. Large magnetoresistance was also observed below $100 $K.