Synthesis of chain-type SrCuO2 by laser irradiation on sputtered layer-type SrCuO2 film

We prepared SrCuO2 film by radio-frequency magnetron sputtering on silica glass and have investigated structure change induced by super-band-gap light. An X-ray diffraction pattern shows that the as-sputtered film is composed of (001)-oriented SrCuO2 nanothick crystals belonging to tetragonal system, i.e., the layer-type SrCuO2. Raman-scattering spectra show that irradiation of high-power super-band-gap laser light onto the film gives rise to structure change into orthorhombic system, i.e., the chain type SrCuO2, which is known to exhibit high, anisotropic thermal conductivity due to spin interaction. A mechanism of the structure change is discussed in terms of photoexcitation and heating process.