Carbon-doped ZnO: A New Class of Room Temperature Dilute Magnetic Semiconductor

TL;DR

This paper demonstrates that carbon doping in ZnO induces room-temperature ferromagnetism, confirmed through first-principles calculations and experiments, suggesting a new approach to creating dilute magnetic semiconductors.

Contribution

It introduces carbon as a non-metal dopant in ZnO to achieve room-temperature ferromagnetism, supported by theoretical predictions and experimental validation.

Findings

Carbon doping results in ferromagnetism with T_C > 400 K.

Measured magnetic moments align with theoretical predictions.

Doped films exhibit n-type semiconducting behavior with intrinsic ferromagnetism.

Abstract

We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78 $\mu_B$ per carbon. The theoretical prediction was confirmed experimentally. C-doped ZnO films deposited by pulsed laser deposition with various carbon concentrations showed ferromagnetism with Curie temperatures higher than 400 K, and the measured magnetic moment based on the content of carbide in the films ($1.5 - 3.0 \mu_B$ per carbon) is in agreement with the theoretical prediction. The magnetism is due to bonding coupling between Zn ions and doped C atoms. Results of magneto-resistance and abnormal Hall effect show that the doped films are $n$-type semiconductors with intrinsic ferromagnetism. The carbon doped ZnO could be a promising room temperature dilute magnetic semiconductor (DMS) and our work demonstrates possiblity of produing DMS with non-metal doping.