The spin-polarization and magnetic coupling character of N-doped SrTiO3 and BaTiO3 are studied through first-principles calculations. The substitutional N doping at O sites leads to a half-metallic property and produces a magnetic moment of 1.0 {\mu}B. The magnetic interaction between the nearest and next-nearest N dopants results in a strong ferromagnetic coupling. When the distance between the N dopants is larger than 7 {\AA}, the ground state of the system tends to be paramagnetic. A nitrogen-concentration threshold to produce the ferromagnetism is estimated. The calculated results give a good explanation for the experimentally observed ferromagnetism in N-doped SrTiO3 and BaTiO3.
@article{arxiv.1110.2138,
title = {First-principles characterization of ferromagnetism in N-doped SrTiO3 and BaTiO3},
author = {Kesong Yang and Ying Dai and Baibiao Huang},
journal= {arXiv preprint arXiv:1110.2138},
year = {2012}
}
Comments
Accepted by Appl. Phys. Lett.; 4 pages, 3 figures; submitted