  The ability to pattern the location of pillars in epitaxial matrix-pillar
nanocomposites is a key challenge to develop future technologies using these
intriguing materials. One such model system employs a ferrimagnetic
CoFe$_{2}$O$_{4}$ (CFO) pillar embedded in a ferroelectric BiFeO$_{3}$ (BFO)
matrix, which has been proposed as a possible memory or logic system. These
composites self-assemble spontaneously with pillars forming through nucleation
at a random location when grown via physical vapor deposition. Recent results
have shown that if an island of the pillar material is pre-patterned on the
substrate, it is possible to control the nucleation process and determine the
locations where pillars form. In this work, we employ electron microscopy and
x-ray diffraction to examine the chemical composition and microstructure of
patterned CFO-BFO nanocomposites. Cross-sectional transmission electron
microscopy is used to examine the nucleation effects at the interface between
the template island and resulting pillar.Evidence of grain boundaries and
lattice tilting in the templated pillars is also presented and attributed to
the microstructure of the seed island.
