Abstract
The two fold degeneracy inherent to epitaxial growth of high T c films on (101) perovskite substrates has been removed successfully. This is demonstrated by single domain, (103) oriented La 2-x Sr x CuO 4 films of 0.04≤x≤0.34 on vicinal (101) SrTiO 3 substrates using 90°off-axis sputtering. (101) substrates that have the surface normal rotated about [010] by 0.5°-3.5°produced essentially single crystal films with the c-axis direction determined by the sense of the miscut. Misoriented antidomains (103)' have been eliminated effectively to a percentage less than 1 part in 10 4 . The mechanism for symmetry breaking is understood on the basis of a surface step model in which the energetics promoting single domain growth is derived from nucleation and epitaxy on the (001) face found at surface steps of vicinal substrates. Furthermore, the incommensuration of the c axis interplanar spacings with the a, b, plane lattice parameters in the La 2-x Sr x CuO 4 structure provides a natural selection of (103) domains over (103)' domains. The model predicts the application to other high T c materials such as the Bi 2 Sr 2 Ca n Cu n +1O x , and the Tl 2 Ba 2 Ca n Cu n +1O x families.