Effect of W co-doping on the optical, magnetic and electrical properties of Fe-doped BaSnO <inf>3</inf>

The effect of W co-doping on the optical, magnetic and electrical properties of Fe-doped BaSnO 3 has been studied. Polycrystalline BaSnO 3, BaSn 0.96Fe 0.04O 3 and BaSn 0.95Fe 0.04W 0.01O 3 samples were prepared using solid state reaction. In the analysis of powder X-ray diffraction patterns, the samples were found to be free of secondary phases. Diffuse reflectance spectra evidenced the substitution of Fe and W for Sn in the host BaSnO 3. Micro-Raman spectra confirmed the existence of oxygen vacancies in the samples. Upon W-1% co-doping, the ferromagnetic character of Fe-4% doped BaSnO 3 is suppressed drastically and its Curie temperature is reduced to 310 K from 462 K. The existence of F-centers and ferromagnetic interactions at room temperature is evidenced by the electron paramagnetic resonance and ferromagnetic resonance signals observed in the electron spin resonance spectra of the undoped and Fe-4% doped, (Fe-4% and W-1%) co-doped BaSnO 3 samples respectively. Suppression of ferromagnetism upon W co-doping is due to the fact that each W 6 ion donates two electrons to the host lattice and it reduces the number of oxygen vacancies that are essential for ferromagnetism to exist in the Fe-doped BaSnO 3 samples. © 2012 Elsevier B.V. All rights reserved.