Nanostructural characterization of EuBa2Cu3Oy layers containing 3.5 mol%BaHfO3 nanorods grown by pulsed laser deposition growing in both vapor–solid and vapor–liquid–solid modes

Abstract

We characterize nanostructures of two types of EuBa2Cu3Oy (EuBCO) layers containing 3.5 mol%BaHfO3 (BHO) nanorods fabricated by pulsed laser deposition (PLD) process using scanning electron microscopy (SEM), transmission electron microscopy and three-dimensional reconstructions that used a series of cross-sectional SEM images taken in a focused ion beam (FIB)-SEM system. One type of PLD layer was grown in a vapor–solid (V–S) mode, and the other was grown in a vapor–liquid–solid (V–L–S) mode. Relatively large polycrystalline of CuO and Ba–Cu–O phases were found on the surface of EuBCO layer grown in the V–L–S mode, consistent with precipitation from liquid phase. Misoriented EuBCO grains with different orientations to those of the matrix grains nucleated on CuO grains (or clusters of CuO/Ba–Cu–O grains) in both EuBCO layers. Both the self-field and in-field critical current values of the EuBCO layers containing BHO nanorods depend on the volume fraction of the misoriented grains, and thus the V–L–S mode layer exhibits better superconductive properties. The volume fraction of the misoriented EuBCO grains in the matrix of c-axis oriented EuBCO grains grown in the V–L–S mode was smaller than that of those grown in the V–S mode.