Structural, magnetic and hyperfine interactions at the Fe sites of Fe-doped SnO

L. A. ERRICO; M. WEISSMANN

Buenos Aires

Workshop; Workshop "At the Frontiers of Condensed Matter physics IV"; 2008

Comite internacional

Tin oxides SnO and SnO2 have been a topic of interest in the last few years due to their technological importance and industrial applications. In fact, tin dioxide is used in many devices where transparent semiconductors are needed, such as thin heat reflecting foils, transparent electrodes, gas sensors, and solar panels, among others. In most cases, impurities are included in order to improve the response of the material. As an example, the interest in SnO$_2$ was recently renewed due to the discovery of high-temperature ferromagnetism in Sn1-xCox$O2 films [Ogale et al., Phys. Rev. Lett. 91, 77205 (2003)] with potential applications in spintronics. Also, in 2005, Punnoose et al [Phys. Rev. B 72, 054402 (2005)] reported the development of room-temperature ferromagnetism in chemically synthesized powder samples of Sn1-xCoxO2 samples and paramagnetic behaviour in Sn1-xCoxO samples. Results for the hyperfine interactions at 57Fe (measured by Mossbauer spectroscopy) were also reported. We present here our first results of a Density Functional Theory-based ab initio study of Fe-doped SnO. Calculations were performed assuming that Fe ions replace Sn indigenous atoms of the structure and including vacancies, in order to discuss their role in the hyperfine interactions and in the magnetic solutions. In all cases, the equilibrium atomic positions and electronic structure of the systems were determined and the hyperfine parameters at the Fe sites were obtained and compared with available experimental data.