Here we present a study of magnetism in \CTO\ anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transition electron microscopy analyses indicate that a high deposition rate leads to a homogeneous microstructure, while very low rate or postannealing results in cobalt clustering. Depth resolved low-energy muon spin rotation experiments show that films grown at a low oxygen partial pressure (≈10−6 torr) with a uniform structure are fully magnetic, indicating intrinsic ferromagnetism. First principles calculations identify the beneficial role of low oxygen partial pressure in the realization of uniform carrier-mediated ferromagnetism. This work demonstrates that Co:TiO2 is an intrinsic diluted magnetic semiconductor.
@article{arxiv.1612.02235,
title = {Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO$_2$},
author = {H. Saadaoui and X. Luo and Z. Salman and X. Y. Cui and N. N. Bao and P. Bao and R. K. Zheng and L. Tseng and Y. H. Du and T. Prokscha and A. Suter and T. Liu and Y. R. Wang and S. Li and J. Ding and S. P. Ringer and E. Morenzoni and J. B. Yi},
journal= {arXiv preprint arXiv:1612.02235},
year = {2016}
}