Microstructural studies of Tl2Ba2Ca2Cu3Ox thin films on LaAlO3 and MgO substrates.

Bramley AP, Wilkinson AJ, Jenkins AP, Grovenor CRM

Tl(2)Ba2Ca(2)Cu(3)O(x) thin films have been fabricated on (001) LaAlO3 and (001) MgO substrates. Films grown on LaAlO3 have T-c=112K and R-s(80K, 10GHz)=0.2m Ohm, while films on MgO have T-c=117K and R-s(80K; 10GHz)=0.7m Ohm. The grain size and alignment of the Alms has been investigated using X-ray diffraction, Scanning Electron Microscopy and Electron Backscattered Diffraction. We show evidence for a markedly higher in-plane angular spread for films on MgO and believe that for films grown on this substrate the lowest achievable values of R-s are limited by disorder in the in-plane alignment of the TBCCO film caused by the large lattice mismatch between the materials.

Keywords:

microstructure

,

SUPERCONDUCTOR

,

EBSD

,

surface resistance

,

TBCCO