Micromechanical Model for Self-Organized Impurity Nanorod Arrays in Epitaxial YBCO Films

A micromechanical model based on the theory of elasticity has been developed to study the configuration of self-assembled impurity nanostructures in high temperature superconducting YBCO films. With the calculated equilibrium strain and elastic energy of the impurity doped film, a phase diagram of lattice mismatches $vs.$ elastic constants of the dopant was obtained for the energetically-preferred orientation of impurity nanorods. The calculation of the nanorod orientation and the film lattice deformation has yielded an excellent agreement with experimental measurements.