Ya Shen, Guofang Zhang, Chengshan Li, Zeming Yu, Lihua Jin, Yao Wang, Yafeng Lu
May 18, 2013
Epitaxial films of rare-earth zirconates, RE 2 Zr 2 O 7 (RE = La, Nd, Sm and Gd) were grown on yttrium stabilized zirconia (100) single crystal substrates using metal-organic deposition. A precursor solution of 0.25 '0.40 M concentration of total cations was spin-coated on yttrium stabilized zirconia substrates and crystallized at 1 000 8C for 3 h in Ar-4%H 2 after calcination at 500 8C for 1 h. X-ray diffraction studies showed that the resulting pyrochlore RE 2 Zr 2 O 7 films were highly textured with cube-on-cube epitaxy. Atomic force microscopy investigations revealed that the surfaces of La 2 Zr 2 O 7 , Nd 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 films had a fairly dense and smooth microstructure without cracks and porosity, but that voids could be seen on the surface of the Gd 2 Zr 2 O 7 film. Optical microscopy measurements confirmed that the Gd 2 Zr2O 7 precursor solution showed poor wetting behavior on the substrate. It was concluded that the Nd 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 films could be potentially used as buffer layers for YBa 2 Cu 3 O 7 -d coated conductors.