Synthesis and Characterization of Ru-doped BaSnO₃Thin Films and Heterostructures

Epitaxial doped stannate thin films have been identified recently as high mobility oxide semiconductors that could form the foundation of an all-oxide electronics. Adding magnetic functionality to this class of materials may provide for a spin-based electronics. Toward this end, we have grown epitaxial thin films of Ru doped BaSnO₃(BSO) and multilayers of alternating La doped and Ru doped BaSnO₃ on (001) SrTiO₃substrates using pulsed laser deposition. X-ray photoelectron spectroscopy was used to verify successful incorporation of both La and Ru into the BSO lattice. X-ray diffraction measurements confirm epitaxial growth of the single layer and multi-layered films. Both single layer and multi-layered films are under epitaxial tensile strain according to X-ray diffraction. Omega rocking curves of both types of samples show excellent crystallinity with typical FWHM values of 0.096^○ and 0.073^○. Both types of films exhibit a paramagnetic response which saturates at approximately 1μ_B/Ru⁴⁺, thus indicating paramagnetism but no ferromagnetic order. Single layer Ru doped BSO films exhibit insulating behavior while layered films have a typical mobility value of 37 cm²/Vs, carrier concentration of 110¹⁹cm^-3and resistivity of 0.4 mΩcm at 300K.