Structure, magnetic and optical properties, and Hall effect of Co- and Fe-doped SnO2 films

Magnetically doped SnO2 is a promising dilute magnetic semiconductor and may also be applicable in a variety of magneto-optical applications. Epitaxial films of Sn1-xCoxO2 (x <= 0.2) and Sn1-xFexO2 (x <= 0.4) were grown by pulsed-laser deposition on R-plane Al2O3 substrates. Structural, magnetic, and magnetotransport measurements consistently point to a source of magnetism within the host lattice rather than from an impurity phase. The films are strained and their magnetic anisotropy is consistent with the presence of substantial amounts of magnetoelastic high-spin Fe2+, or high- or low-spin Co2+. Sn0.9Co0.1O2 films have a reasonably high Faraday rotation of 570 degrees/cm, and the refractive index n and extinction coefficient k at 1550 nm wavelength are 1.957 and 0.0102, respectively.