Room-temperature ferromagnetism and oxygen pressure-dependent optical, ferromagnetic properties in SrSn_0.5Co_0.5O₃ thin films

Room-temperature ferromagnetism was obtained in SrSn_0.5Co_0.5O₃ (SSCO) epitaxial film on SrTiO₃ substrate by pulsed laser deposition, and the effects of oxygen pressure (P_O2) on the microstructure, optical and magnetic properties were examined. An interesting hybrid epitaxial film embedded with polycrystalline SSCO and SrCoO_x nanoparticles was observed. The increase of P_O2 relaxed the film/substrate compressive strain, promoted the growth of crystallites and reduced the optical band gap (from 2.43 to 1.68 eV). The SSCO film deposited at 0.1 Pa exhibited good ferromagnetism at 100–300 K, while the ferromagnetism in the film with higher and lower oxygen pressure (1 Pa and 10⁻⁴ Pa) was weak.

Room-temperature ferromagnetism and tunable optical band gap (2.34–1.68 eV) were demonstrated in Co-doped SrSnO₃ thin film grown on SrTiO₃ single-crystal substrate by pulsed laser deposition with varying oxygen pressure.