Preparation of c-Axis Oriented SmBa2Cu3O6+δ Thin Films with a Buffer Layer

Abstract

It is reported that SmBa2Cu3O6+δ (Sm123) shows better superconducting properties under high magnetic fields in comparison with YBa2Cu3O7-y (Y123). We have investigated Y123 thin film deposited on MgO with SrTiO3 (STO) buffer layer (STO/MgO)[l]. To improve the superconducting properties, we discussed the factors affecting the critical temperature of Sml23 thin films deposited on MgO, STO and STO/MgO substrates. We have obtained c-axis oriented Sml23 thin films on MgO, STO and STO/MgO substrates. However, we hardly obtained c-axis oriented Sml23 thin film, when we used STO (100) buffer layer in which (110) intermingled. From atomic force microscopy, the roughness of STO (100) buffer layer in which (110) intermingled was large, compared with STO (100) buffer layer. We speculate that the orientation and the large roughness of the STO buffer layer are the reason why we could not obtain c-axis oriented Sml23 thin films.