We present a comparative study in terms of structural properties deduced from X - ray diffraction diagrams between YBa2Cu3O7 (YBCO) thin films fabricated on SrTiO3 (STO) single crystal substrates and bicrystallines substrates with a symmetrical tilt angle of 24 degrees. Periodic Lattice Distortions (PLD) have been observed around different Bragg peaks in YBCO thin films deposited on STO bicrystals while only diffraction peaks have been measured in the diagrams corresponding to the YBCO thin films deposited on STO single crystal substrates. Only in regions situated a 3.5 mm at both sides of the grain boundary the PDL have been investigated. Scans along different (h, k, l) directions allow us to conclude that the qPLD vector associated to the distortion is along the (h,-k,0) direction. However, we found that the amplitude of the components of the qPLD vector depend on the Bragg peak chosen. We believe such a result indicates that we have not a PDL with a simple qPLD vector. In this line, other (h, k, l) directions must be investigated to deduce the exact origin of the qPLD vector. Nevertheless, independently on the qPLD vector associated to the PLD, we believe that such a distortion in the lattice is a consequence of the stress field induced by the grain boundary in the YBCO thin film deposited on the bricrystal.
M. Navacerrada, A. Mehta, H. Sahibudeen, and Juana Acrivos. "Comparative Study of Structural Properties of YBa2Cu3O7 Thin Films on SrTiO3 Single Crystal and Bicrystal Substrates by X- ray Diffraction" Materials Research Society Symposium Proceedings (2005).