Title :
Growth properties of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7- delta / thin film on CeO/sub 2/(/MgO) buffer layer for the biepitaxial boundary function
Author :
Youm, D. ; Lee, S.
Author_Institution :
Korean Adv. Inst. of Sci. & Technol., Taejon, South Korea
fDate :
3/1/1993 12:00:00 AM
Abstract :
In the fabrication of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7- delta / (YBCO)/CeO/sub 2//MgO/SrTiO/sub 3//SrTiO/sub 3/ biepitaxial grain boundary junctions, the substrate temperature window for the growth of good quality superconducting YBCO overlayers on CeO/sub 2//MgO/SrTiO/sub 3/ is lower and narrower than for growth of YBCO on CeO/sub 2//SrTiO/sub 3/. Results of X-ray diffraction 2 theta and phi scan measurements reveal that the lattice structure of the CeO/sub 2/ layer on the MgO seed layer is 2 approximately 3 times more distorted than for CeO/sub 2/ on a bare SrTiO/sub 3/ substrate. It is found that the instability of the crystal formation of the YBCO layer on the CeO/sub 2//MgO/SrTiO/sub 3/ is accompanied by the loss of stoichiometry at slightly higher substrate temperature.<>
Keywords :
X-ray diffraction examination of materials; barium compounds; grain boundaries; high-temperature superconductors; interface structure; sputter deposition; stoichiometry; superconducting epitaxial layers; superconducting thin films; vapour phase epitaxial growth; yttrium compounds; CeO/sub 2/ layer; MgO seed layer; X-ray diffraction; YBCO overlayers; YBa/sub 2/Cu/sub 3/O/sub 7- delta /-CeO/sub 2/-MgO-SrTiO/sub 3/; biepitaxial boundary function; biepitaxial grain boundary junctions; buffer layer; high temperature superconductors; instability; lattice structure; sputtered coating; stoichiometry; substrate temperature window; thin film; Distortion measurement; Fabrication; Grain boundaries; Josephson junctions; Lattices; Nonhomogeneous media; Substrates; Temperature distribution; Transistors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
